primergy duplexdatamanager help - fujitsu...

Fujitsu Technology Solutions 2010

PRIMERGY DuplexDataManager® Help

DDM 5.01 help extraction

November 17, 2010

Contents

1 OVERVIEW .................................................................................................... 4

1.1 DuplexWrite ......................................................................................................................................... 4

1.1.1 Data Duplexing .............................................................................................................................. 4

1.1.2 Dynamic Diskload Balancing .................................................................................................... 5

1.1.3 DuplexWrite Group ...................................................................................................................... 5

1.1.4 Data Recovery ............................................................................................................................... 5

1.1.5 CloneData ........................................................................................................................................ 6

1.1.6 Event Logging ................................................................................................................................ 6

1.2 MultiPath ............................................................................................................................................... 6

1.2.1 Failover Policy ................................................................................................................................ 7

1.2.2 Error Recovery ............................................................................................................................... 7

1.2.3 AutoFailback ................................................................................................................................... 8

1.2.4 Automatic Load Balancing ......................................................................................................... 8

1.2.5 Path Monitoring ............................................................................................................................. 8

1.2.6 Event Logging ................................................................................................................................ 8

1.2.7 MPIO Error Handling, Failover and Recovery ..................................................................... 9

1.2.8 MPIO Dynamic Load Balancing ................................................................................................ 9

2 HANDLE PRIMERGY DUPLEXDATAMANAGER® ................................10

2.1 Manage PRIMERGY DuplexDataManager® ........................................................................10

2.2 Setting up a DuplexWrite Disk ................................................................................................11

PRIMERGY DuplexDataManager Help 5.01

Fujitsu Technologie Solutions November 17, 2010 2 / 67

2.3 Breaking up a DuplexWrite Group .........................................................................................12

2.4 Handle Disk Errors ..........................................................................................................................13

2.5 Microsoft Windows Clustering Support ..............................................................................14

2.6 Setting up a RootDisk ...................................................................................................................15

3 DUPLEXDATAMANAGER INSTALLATION ...........................................17

3.1 Installation ..........................................................................................................................................17

3.2 Uninstallation ....................................................................................................................................18

4 MMC SNAP-IN FOR DDM .........................................................................18

4.1 Node DuplexDataManager .........................................................................................................18

4.2 Node DuplexWrite ...........................................................................................................................20

4.3 Node DuplexWrite Group ............................................................................................................26

4.4 Node MultiPath .................................................................................................................................32

4.5 Node MultiPath Group ..................................................................................................................38

4.6 Node SCSI view ................................................................................................................................42

4.7 Node SCSI port .................................................................................................................................44

5 DUPLEXDATAMANAGER STATUS ..........................................................47

5.1 DuplexWrite Status ........................................................................................................................47

5.2 MultiPath Status ...............................................................................................................................48

6 PROPERTY SHEETS....................................................................................48

6.1 DuplexDataManager ......................................................................................................................48

6.2 DuplexWrite ........................................................................................................................................50

6.3 DuplexWrite Group .........................................................................................................................50



6.4 DuplexWrite Piece ..........................................................................................................................52

6.5 MultiPath ..............................................................................................................................................55

6.6 MultiPath Group ...............................................................................................................................57

6.7 MultiPath Path ...................................................................................................................................59

6.8 SCSI Port ..............................................................................................................................................61

6.9 SCSI Device .........................................................................................................................................63

7 TECHNICAL INFO .......................................................................................66

7.1 How to find different paths to one disk .............................................................................66

7.2 How to find a DuplexWrite group ..........................................................................................66

7.3 System / Boot Partition ...............................................................................................................66

7.4 COD Partition .....................................................................................................................................67



1 Overview

PRIMERGY DuplexDataManager® (DDM) is the software solution for PRIMERGY servers

which allow disk subsystems to be provided redundantly over large distances. It offers

high availability in terms of connection and storage system failures. In combination with Microsoft Windows Clustering (MSCS) a full disaster-tolerant configuration can be set up.

PRIMERGY DuplexDataManager® combines two components:

DuplexWrite mirrors data to an additional, remote storage

MultiPath ensures redundant data paths to the disk storage units

Currently there are two editions available:

PRIMERGY DuplexDataManager®: DuplexWrite and MultiPath

PRIMERGY MultiPath: MultiPath only

PRIMERGY MultiPath MPIO: Multi-path via Microsoft MPIO only

1.1 DuplexWrite

DuplexWrite is the DDM component for data mirroring. DuplexWrite duplicates write

operations so that two disks of different disk storages contain identical data. This solution

is a so-called 'physical mirroring' because it is independent of logical data structures such

as file systems.

If one of the disks fails, DuplexWrite ensures that the data will continue to be processed

smoothly by accessing the disk still in service. When the faulty disk has been repaired,

data recovery can be done online while normal operation continues. No reboot is

necessary. This applies to physical disks as well as complex RAID volumes. Even the

system/boot disk (RootDisk) can be replaced online.

The driver design is Microsoft Cluster Services (MSCS) compliant.

Notes:

DuplexWrite is not provided with product MultiPath.

DuplexWrite only supports Basic Disks.

DuplexDataManager/MultiPath does not run if any MPIO device specific module

(DSM) is running on the system.

1.1.1 Data Duplexing

DuplexWrite duplicates each write operation to both members of a DuplexWrite group.

The DuplexWrite group appears to the operating system as one disk. Data is written to

both disks as long as no error condition occurs. As a result, both disks of a DuplexWrite

group contain identical data. Duplexing is done based on disk LUNs, including the virtual

LUNs of a RAID subsystem.



Data is read from one specified disk, called Preferred Disk. This disk can be selected from

the DuplexWrite group. In case of an error - after a number of unsuccessful retries - the

corresponding disk's status is set to Error and the disk will not be used, subsequently.

The error is logged and a notification is sent to the user that this disk has been disabled.

Configuration data and DuplexWrite states are stored on disk. DuplexWrite uses a

special, non-standard partition for Configuration On Disk (COD) storage.

User data remains unchanged and is stored on standard partitions. All (user) data is

mirrored physically.

1.1.2 Dynamic Diskload Balancing

Normally, DuplexWrite uses one disk for read, only. This disk - the Preferred Disk - can

be chosen by the user. Dynamic Diskload Balancing means that read operations are

distributed over both disks. A dedicated algorithm determines the best disk to read from.

I/O speed increases because of

less disk load per device

increased cache hit ratio because of double disk cache

faster seek times by optimal disk selection

Therefore, Dynamic Diskload Balancing increases system performance compared to a

non-DDM installation.

1.1.3 DuplexWrite Group

A pair of redundant disks is called a DuplexWrite group. Both members (partner disks,

pieces) of a DuplexWrite group contain identical (user) data. A DuplexWrite group

appears to the operating system as one disk. Duplexing is done based on disk LUNs,

including the virtual LUNs of a RAID subsystem. Each DuplexWrite group has one

Preferred Disk - by default the first disk - where the data is read from.

A group ID - optional a user defined name - identifies each DuplexWrite group. To avoid

changes by mistake, a common unique key is assigned to both disks. This key is updated

whenever a DuplexWrite group is created or a disk is deleted from a DuplexWrite group.

1.1.4 Data Recovery

In normal operation both disks of a DuplexWrite group contain identical data. In case of

an error the corresponding disk's status is set to Error and the disk will not be used,

subsequently. All data is safe on the remaining partner disk.

Before a disk can be returned to its DuplexWrite group, it has to be updated: All data has

to be copied to the disk. This will be done online while normal operation continues. If a

write operation occurs while data is recovered DuplexWrite synchronizes the write

operation so that a consistent state is guaranteed. When the recover process has been

finished successfully, the disk's status is set to Online, COD data is updated and the disk

becomes a full functional member of the DuplexWrite group again.



1.1.5 CloneData

Use CloneData to copy the data of a DuplexWrite piece to a disk device (full snapshot).

CloneData copies all data of a DuplexWrite piece (= source) to a dedicated destination

device 'physically' (block based - not file based). To get a consistent copy, the source

(one of the two DuplexWrite pieces) has to be disabled while copying. As the source

piece has been disabled it has to be recovered when CloneData is finished. This recover

can be started automatically. Delta Recover is recommended here.

A special algorithm can be used to minimize DuplexWrite group's degradation time: In

non-degraded mode (both pieces online) all blocks are copied once while all modifications

during this phase are logged. In a second phase the source piece is disabled and all

modified blocks are copied again - representing the state at disable time. The time of

degradation is minimal - with the disadvantage of a non-predictable snapshot point in

time. This algorithm is optional.

The CloneData start time can be scheduled (once/daily/weekly).

The CloneData task will only be created if the destination disk has no partitions or

the partitioning is exactly identical to the source disk (DuplexWrite group).

The COD partition will be copied but the partition type will be changed.

CloneData does not change the operating systems disk signature on the

destination disk.

While CloneData is active the destination volumes (not at first time) will be

locked. CloneData cannot start if the destination volume is in use. DuplexWrite

makes up to four attempts to start a scheduled CloneData task.

It is not required to connect the destination disk to a DuplexDataManager

supported port. The port can be disabled for MultiPath or DuplexWrite

functionality.

It is recommended to run CloneData when the system load is low.

1.1.6 Event Logging

All DuplexWrite driver events are logged by the standard system event logging.

Additionally, the events are available to the Alarm Monitor of ServerView as SNMP traps.

1.2 MultiPath

MultiPath is a component of the PRIMERGY DuplexDataManager® and is the software for

administering and operating redundant data paths. MultiPath ensures constant

availability of the communication channel, even if disruptions occur on one of the

connections.

MultiPath requires at least 2 Fibre Channel host adapters per server with full cabling.

MultiPath performs permanent monitoring of these connection paths, via which I/O data

streams are transported from/to the disk storage unit. Even if a fault occurs on a data

path – such as failure of a FC host controller, or cable, hub or switch disruptions –

processing with the server is not interrupted. In such a situation, MultiPath switches to

the second connection path and uses it for accessing the storage. The applications



continue running without any disruption and the availability of the entire server

installation is significantly increased.

The driver design is independent on the underlying Fibre Channel host adapter. The

design is not tailored to a specific storage. Support for special storage can be added

easily. The driver design is Microsoft Cluster Services (MSCS) compliant.

The Microsoft MPIO solutions are designed to work in conjunction with device specific

module (DSMs) written by vendors. The package MultiPath MPIO provides the familiar

MMC snap-in and the path monitoring via SNMP.

Note: DuplexDataManager/MultiPath does not run if any MPIO device specific module

(DSM) is running on the system.

1.2.1 Failover Policy

Failover from one path to the other is initiated as soon as an error condition is detected.

That error might be caused by a defect controller or cabling (typical: timeout). As

reaction to one of these error conditions the MultiPath filter driver issues the following

SCSI commands:

Operating system special handling:

Windows 2000: BUS RESET (as target reset is not fully implemented in

Windows 2000)

Windows 2003: Send a LUN-Reset to the device. If the device does not

support this, a Device-Reset is sent. If this is also not

supported a BUS-Reset is sent.

Windows 2008: In Windows 2008, SCSI-Reservations are done by “Persistent

Reservation”. To perform a failover of the path, a Preemption

of the Persistent Reservation is done.

TEST UNIT READY

eventually a storage vendor specific command to switch LUNs to the desired port

retry of the command on the other port

Note: On FibreCAT CX storages the special command Trespass must be used to switch

the active path to another Service Processor (SP).

1.2.2 Error Recovery

MultiPath implements an auto recovery feature, which automatically cleans up error

conditions when for example a broken cable has been replaced.



1.2.3 AutoFailback

The MultiPath driver supports an AutoFailback mode: If this mode has been selected

MultiPath will automatically failback to the Preferred path after error recovery. The

Preferred path is selectable by the user.

The Fujitsu FibreCAT SX MPIO DSM also supports AutoFailback, but the feature Preferred

path is not supported. Only supported for Load Balance Policy Fail Over Only.

Note: When AutoFailback is switched on, AutoBalance will be switched off.

1.2.3.1 Manual Load Balancing

To enhance the data transfer rate the active paths of the MultiPath groups can be

distributed across the available SCSI ports. To ensure that the distribution will be

preserved over error situations or reboots the paths must be selected as Preferred paths

and AutoFailback mode must be turned on. For MPIO see below.

Note: When selecting the Preferred path the activation occurs on the first I/O to the

device.

1.2.4 Automatic Load Balancing

To enhance the data transfer rate the paths of the MultiPath groups will be automatically

distributed across the available SCSI ports.

Notes

When AutoBalance is switched on, AutoFailback will be switched off.

Not supported in Microsoft Cluster Server configuration.

Not supported with MultiPath MPIO.

1.2.5 Path Monitoring

If a MultiPath path is not available after a reboot, the MultiPath driver does not know it.

To fix this gap the DuplexDataManager service compares the current MultiPath path

configuration with the stored path configuration. The user stores/acknowledges the

current MultiPath path configuration via the MMC snap-in menu 'Acknowledge

Configuration'. The MultiPath path monitoring cycle time is 5 minutes by default. Missing

paths are logged in the system event log, SNMP traps are generated and an error icon

shows this state in the MMC snap-in.

1.2.6 Event Logging

All MultiPath driver events are logged by the standard Windows event logging.

Additionally, the events are available to the Alarm Monitor of ServerView as SNMP traps.



1.2.7 MPIO Error Handling, Failover and Recovery

The MPIO driver package, in combination with the vendor DSM, supports end-to-end path

failover. The process of detecting failed paths and recovering from the failure, like load

balancing, is automatic, extremely fast, and completely transparent to the IT

organization. The data remains available at all times.

Not all errors result in failover to a new path. Some errors are temporary and can be

recovered using a recovery routine in the DSM; if recovery is successful, MPIO is notified

and path validity checked to verify that it can be used again to transmit I/O requests.

When a fatal error occurs, the path is invalidated and a new path is selected. To do this

correctly, outstanding I/Os must be returned to a higher level in the stack. Once this is

done, all devices on that path can be removed and then failed over to the new path.

1.2.8 MPIO Dynamic Load Balancing

Load balancing, the redistribution of read/write requests for the purpose of maximizing

throughput between server and storage device, is especially important in high workload

settings or other settings where consistent service levels are critical. Without

multipathing software, a server sending I/O requests down several paths may operate

with very heavy workloads on some paths while others are underutilized.

The Microsoft MPIO software supports the ability to transparently balance I/O workload,

without administrator intervention. MPIO determines which paths to a device are in an

active state and can be used for load balancing. Each vendor’s load balancing policy

(which may use any of several algorithms, such as round robin, the path with the fewest

outstanding commands, or a vendor unique algorithm) is set in the DSM. This policy

determines how the I/O requests are actually routed. If the DSM returns a path that is

inactive, the failover process is initiated.



2 Handle PRIMERGY DuplexDataManager®

2.1 Manage PRIMERGY DuplexDataManager®

PRIMERGY DuplexDataManager® provides two different user interfaces:

Local or remote administration via Microsoft's Management Console (MMC).

DuplexDataManager provides the MMC snap-in 'Configuration Snap-in' for

administration.

In the current ServerView version, the SNMP traps monitored. In addition, the

status of the MultiPath MPIO SNMP agent processed in the ServerView Status

Agent.

Additional: The older ServerView version supports the graphical tree view of the

MultiPath configuration. It can be accessed via ServerView's sub dialog

Mass Storage > DDM View.

For further information see ServerView's integrated help.

To enter DuplexDataManager administration:

Select entry 'Configuration Snap-in' from Start menu: Programs > Fujitsu > PRIMERGY DuplexDataManager.

The Microsoft Management Console will show up with the snap-in

'DuplexDataManager'.

Use the MMC node DuplexDataManager (local) for local administration.

To manage a remote system:

Right click on MMC node 'DuplexDataManager' and select 'Connect to another

computer...'

Follow the connect dialog...

Use the MMC node DuplexDataManager (<host>) for remote administration.

You must have host administrator rights to manage DuplexDataManager.



2.2 Setting up a DuplexWrite Disk

To set up a DuplexWrite disk proceed as follows:

Make sure to have a free partition entry and enough disk space for the COD.

Enter MMC snap-in dialog DuplexDataManager.

Select snap-in node SCSIView > SCSIPort.

Select desired disk and click (right mouse button) menu action Create

A dialog will show up: Enter a DuplexWrite group name.

Select the location of the COD partition.

Confirm creation of the DuplexWrite group.

DuplexWrite initializes the COD partition.

The status is Online.

or

Make sure to have a free partition entry and enough disk space for the COD.


Select snap-in node DuplexWrite and click (right mouse button) menu action

Create

A dialog will show up: Select desired disk and enter a DuplexWrite group name.

Select the location of the COD partition.

Confirm creation of the DuplexWrite group.


The status is Online.

In the dialog select where the Configuration On Disk (COD) partition will physically be

located on disk. By default DuplexDataManager creates the COD at the beginning of mirrored space.

In RootDisk group (system/boot disk) case the preferred location of the COD is at the

end of the mirrored space.

The DuplexWrite group is now available and can be used. User partitions can be created

using Disk Management.

To create the partner disk (2nd piece) proceed as follows:

Use Disk Management to clean disk: remove all partitions or remove driver

letters.

All previous disk data will be destroyed!


Select snap-in node DuplexWrite.



Select desired DuplexWrite group and click (right mouse button) menu action Add

A dialog will display a list of all available disks.

Select a disk from the list. It will be added as second piece to the DuplexWrite

group. The disk size must be equal or greater than the DuplexWrite group size.

No user data will be affected.

The new disk status is Error. Start Recover to set the second disk online. The

second piece will set immediately online if the first piece is empty. A disk is

empty, if there is no any partition is available except the DuplexDataManager COD

partition.

DuplexWrite supports Basic Disks, only. GUID partition table (GPT) Disks and Dynamic

Disks are not supported. The disk layout/partitioning must be suited for DuplexWrite. Otherwise, the creation is rejected.

DuplexWrite uses a primary partition to store the COD. The size of this partition is at

least 32 MB. If there is no partition available, one primary partition must be deleted. If

there is no space on the disk to create the COD, the partitions must be resized before setup.

Do not delete a COD partition by Disk Management while DuplexDataManager is

installed. This would lead to unpredictable errors! Delete a COD partition first by the

DuplexWrite group command Delete Group. This will change the partition type from 'Healthy' to 'Unallocated'.

In Microsoft Cluster (MSCS) installations shutdown the other node(s) before any

configuration changes (e.g. create/add of DuplexWrite group). This avoids an inconsistent view of the storage resources.

2.3 Breaking up a DuplexWrite Group

To break a DuplexWrite group:

Use DuplexDataManager Configuration Snap-in for administration.

Select Snap-in node for the DuplexWrite group

Select the desired piece and click (right mouse button) menu action Disable. For

RootDisks only the 2nd piece is selectable.

Select it again and click (right mouse button) menu action Delete Piece.

The old disk signature is deleted and the disk can be used as a normal disk again.

In case of a RootDisk the master boot record (MBR) will be deleted.

All user data is retained on the first piece. Applications will proceed without any

disruption.

Alternatively, one piece (disk) can be physically removed.



2.4 Handle Disk Errors

DuplexWrite disks are maintained by MMC snap-in node DuplexWrite Group. Use this

snap-in entry to observe and change disk status. Detailed disk information is available by

double clicking on the desired disk entry (submenu Properties).

This section describes different error situations and the recommended user action.

One piece is in status Error:

All data can be recovered from the partner disk: Select piece with DuplexWrite status

Error and click (right mouse button) menu action Recover.

In case of a disk hard error exchange the defect disk first. If the disk is hot swappable

this can be done online. Make sure that the replacement disk has the appropriate size.

One piece is missing:

When the failing disk (LUN) has been removed it is still known from the COD data of the

partner disk - even after a reboot. It will subsequently be listed as missing.

Before a new disk (LUN) can be added to the current DuplexWrite group the missing

entry has to be deleted: Select piece and click (right mouse button) menu action Delete

Missing Piece. The attribute missing will be deleted.

Now, a new disk can be added by menu action Add.

Both pieces are in status Error:

When both disks are in status Error the DuplexWrite group is not available to the

application anymore. From operating system point of view this situation shows up like a

disk failure. Further reaction depends on the application. DuplexWrite ensures that all data written previously to this double-error situation is safe.

Choose the disk with the most recent data for data retrieval. Open Properties for both

pieces to get the information on last update. Find most recent disk (flag Recent set),

select it and click (right mouse button) menu action Online. This will set the selected

piece Online. Now select the other (not most recent) piece and click (right mouse button)

mk:@MSITStore:D:/Views/Top/SrvView_Agents/NT/DDM/Help/ddmsnap.chm::/NodeDwGroup.htm

mk:@MSITStore:D:/Views/Top/SrvView_Agents/NT/DDM/Help/ddmsnap.chm::/Properties_DwDisk.htm

mk:@MSITStore:D:/Views/Top/SrvView_Agents/NT/DDM/Help/ddmsnap.chm::/NodeDwGroup.htm#Online



menu action Recover. The DuplexWrite status of this piece will change to Recover, later

on to Online.

Now, proceed as described for one disk in status Error (see above).

In case of MS cluster configurations be aware of misinterpretation of shown data (see

section on MS Clustering Support for more information).

2.5 Microsoft Windows Clustering Support

The Microsoft Windows Clustering (MSCS) provides additional host failure tolerance and

can be combined with DuplexWrite and/or MultiPath to achieve full disaster-tolerance.

Even if DuplexWrite uses a duplexing method, which is transparent to the application,

special handling for MSCS is necessary:

Disks are shared among cluster nodes. The configuration data and states can be

changed by another node.

MSCS uses the SCSI commands RESERVE and RELEASE. A reserve command

makes a disk inaccessible for all other nodes.

DuplexDataManager uses the MS cluster service to get further information. This enables

DuplexWrite to get additional information on shared disks that are currently assigned to

another node.

Following example demonstrates the effects of SCSI reservation:

Consider a cluster system composed of two nodes A and B. Both pieces of the

shared DuplexWrite group are currently assigned to node A. Because of the SCSI

reservation these disks cannot be read from node B. The COD data is inaccessible.

Because of the DDM cluster service these disks are known and listed as cluster

resources.

When DuplexDataManager has problems connecting to the MS cluster service both pieces

will appear to node B similar to defect DuplexWrite disks.

DuplexWrite group as seen from node A; 2nd disk currently recovering:

Same DuplexWrite group as seen from node B; disks already known to DuplexWrite as

configured for MSCS:

If a disk is reserved by another cluster node only SCSI bus information is available. The

configuration data, even disk sizes cannot be obtained. Use the SCSI bus information for

disk identification.

mk:@MSITStore:D:/Views/Top/SrvView_Agents/NT/DDM/Help/ddmsnap.chm::/NodeDwGroup.htm#Recover

mk:@MSITStore:D:/Views/Top/SrvView_Agents/NT/DDM/Help/ddmsnap.chm::/DwClusterSupport.htm



When the second cluster node has finished booting it is possible that some DuplexWrite

disks or even DuplexWrite groups are not displayed. This can be overcome by moving all cluster resources from the first node to the second node.

Be aware of misinterpretation of shown data, especially when both pieces are in status

Error, like:

Check other node's view first. It must show both pieces like:

Otherwise, cluster communication is broken, or MMC snap-in data needs to be refreshed.

After booting a cluster node move all disk resources once to all cluster nodes so that

DuplexWrite takes over the DuplexWrite configuration.

If Refresh or Rescan does not show the correct data, the DuplexDataManager Service

should be restarted.

After restarting the Cluster Service the DuplexDataManager Service must be restarted

too.

MSCS is a high available cluster solution - not a fault tolerant solution. For this reason

the default behavior for DuplexWrite is to continue operation even if one piece of a

DuplexWrite group is missing. If all interconnects (network and storage) between the

clusters nodes are broken, it is, in principle, possible, that two half’s of an MSCS

configuration will continue operating. Take this into consideration when planning your

cabling. On the other hand DuplexWrite can be configured to prevent access to a

DuplexWrite group if one piece is missing - ask for support if you want to use this

feature.

2.6 Setting up a RootDisk

DuplexDataManager supports mirroring of the system/boot disk. This special DuplexWrite

group is named RootDisk.

When preparing the system/boot disk due operating system installation a free area at the

end of the disk must be reserved.

Requirements:

The partition size is aligned according to disk's geometry and thus can be larger

than COD's minimal space requirement of 32 MB. We recommend 39 MB as

minimum.

The COD partition uses a free primary partition.

mk:@MSITStore:D:/Views/Top/SrvView_Agents/NT/DDM/Help/ddmsnap.chm::/NodeDuplexDataManager.htm

mk:@MSITStore:D:/Views/Top/SrvView_Agents/NT/DDM/Help/ddmsnap.chm::/DwSystemDisk.htm

mk:@MSITStore:D:/Views/Top/SrvView_Agents/NT/DDM/Help/ddmsnap.chm::/DwCodPartition.htm



Mark the second LUN (mirror) in controller BIOS as boot LUN. In MultiPath case

there are four entries (Destination Identifier (D_ID), Host Bus Adapter WWPN,

and Storage Controller/Port WWPN) marked as boot LUN.

Restrictions:

For DuplexWrite RootDisk mirroring the system and boot partitions must be on the

same disk.

It is only possible to create DuplexWrite RootDisks on supported controllers and

storages.

To set up a DuplexWrite RootDisk group proceed as follows:

Install the operating system (see requirements).

Install the DuplexDataManager package and restart the system.


Select snap-in node DuplexWrite and click (right mouse button) menu action

Create.

A dialog will show up: Select desired disk and enter a DuplexWrite group name.

Choice the location of the COD partition at the end of the mirrored space.

Confirm to create the DuplexWrite group.


The procedure to add the second disk is described in Setting up a DuplexWrite disk.

The DuplexWrite RootDisk group is featured with '[root] (System)' in the MMC snap-in.

DuplexDataManager filter driver ddm.sys:

On system start all drivers will be loaded.

ntkrnlpa.exe

hal.dll

...

ACPI.sys

WMILIB.sys

PCI.sys

isapnp.sys

ddm.sys

...

ftdisk.sys

...

storport.sys

...

Before ddm.sys is loaded, the system reads from the boot disk. Until that time

there are no writes on the disk. When ddm.sys is loaded all reads and writes are

managed via DuplexDataManager.

mk:@MSITStore:D:/Views/Top/SrvView_Agents/NT/DDM/Help/ddmsnap.chm::/NodeDuplexWrite.htm#Create

mk:@MSITStore:D:/Views/Top/SrvView_Agents/NT/DDM/Help/ddmsnap.chm::/DwSetupDisk.htm#create_the_partner



Special restriction for DuplexWrite RootDisk group:

DuplexWrite does not know from which disk/path the system is booted. Normally

the first piece/disk of the RootDisk is the boot disk. If this piece does not have has

a DuplexWrite status unequal Online (Error or Disabled), the system will boot on

this degraded disk (if it is readable) before ddm.sys is loaded. Please ensure that

the system boots from an Online disk.

If a disk was prepared accidentally use Disk Manager to clear the disk drive. Otherwise, do not modify the COD partition with OS-unknown type!

Do not upgrade to Dynamic Disk. DuplexWrite supports Basic Disks, only.

Please refer for the currently released settings of the fibre channel switches, host bus

adapters and storages.

3 DuplexDataManager Installation

PRIMERGY DuplexDataManager® (DDM) software comes on CD medium. Updates are

available on Fujitsu Technology Solutions download web side.

3.1 Installation

The DuplexDataManager installation procedure:

Be sure to have administrator rights.

Insert CD-ROM 'PRIMERGY DuplexDataManager', 'PRIMERGY MultiPath' or

'PRIMERGY MultiPath MPIO'.

Change to 'CD-ROM:\Packages\Windows' directory. In MPIO case 'CD-

ROM:\Windows'

Use setup*.msi to install the software.

Follow the Installation Wizard.

Reboot the system after successful installation (only if a reboot is required).

For remote administration with the MMC snap-in it is sufficient to install the client (frontend) only: Deselect (uncheck) Service installation in wizard feature dialog.

DuplexDataManager may require some special settings for the host bus adapter and the

RAID storage. Please, check the Readme file.

For remote monitoring (e. g. ServerView) the DuplexDataManager SNMP agent will be

installed. In the program directory of the DuplexDataManager service component a MIB

(Management Information Base) can be found. This MIB describes all

DuplexDataManager management information (traps, ...).



3.2 Uninstallation

Because DuplexWrite disks are true duplicates, the operating system may be confused

seeing the same disk signature twice when DDM is not active. Therefore, all DuplexWrite

groups must be broken up.

For more information, see Breaking up a DuplexWrite Group.

Alternatively, one piece (disk) can be physically removed.

When all DuplexWrite groups have been broken up (deleted) DuplexDataManager can be

uninstalled. Use the standard software uninstallation procedure to remove DuplexDataManager:

Choose 'Add/Remove Programs' from the Control Panel.

Choose 'Fujitsu PRIMERGY DuplexDataManager®', 'Fujitsu PRIMERGY

MultiPath' or 'Fujitsu PRIMERGY MultiPath MPIO' from the list of installed

software.

Click button 'Remove'.

Reboot the system after successful uninstallation. Not needed in 'Fujitsu

PRIMERGY MultiPath MPIO' case.

4 MMC Snap-in for DDM

DuplexDataManager provides the MMC snap-in 'Configuration Snap-in' for administration.

4.1 Node DuplexDataManager

MMC entry to manage PRIMERGY DuplexDataManager®.

It contains the views:

DuplexWrite

MultiPath

SCSI View

DuplexWrite is not provided with MultiPath!

The host name is shown within brackets. e. g. DuplexDataManager (local)

mk:@MSITStore:D:/Views/Top/SrvView_Agents/NT/DDM/Help/ddmsnap.chm::/DwBreakGroup.htm



Action on DuplexDataManager node (right mouse button)

Connect to another

computer...

Select the computer you want DuplexDataManager to manage.

Refresh Refresh all MMC information. Recommended in case of failure situation to be

sure that shown status is the current one.

Rescan devices Rescan SCSI bus for changes/new devices.

This command may have unwanted effects because it restores the current

view of the SCSI bus: For instance a defect MultiPath connection (path) will

be deleted from this view and will not be available further on!

Use this command to overcome suspicious device states, only.

Open archive... Open an archived DuplexDataManager configuration file.

An archive can be used to monitor configuration changes and can help

customer support in maintenance cases. In archive mode only a restricted set of operations is available.

Archive... Archive the current DuplexDataManager configuration into a file.

An archive can be used to monitor configuration changes and can help

customer support in maintenance cases.

Only accessible if a connection to a computer exists.

To archive the configuration into a text file use the DuplexDataManager command line utility ddmutil.exe (e.g. ddmutil -ddm -l > filename.txt).

Set

DuplexDataManager

notification...

Set DuplexDataManager notification on server console. Affects system tray

icon on the server.

Enable system tray icon on server console:

Select to display the DuplexDataManager system tray icon on server console.

View icon in degraded/error state only: Select to display the DuplexDataManager system tray icon only when DuplexDataManager detects degraded or erroneous groups.

'View icon in degraded/error state only' only selectable if 'View icon in degraded/error state only' is enabled.

Only accessible if a connection to a computer exists.

Enter Product Key... Enter the DuplexDataManager Product Key.

You will find this number in the License Paper.

Only accessible for DuplexDataManager and no valid Product Key entered

before.



View Product Key... View the DuplexDataManager Product Key.

Only accessible for DuplexDataManager and a valid Product Key entered

before.

Properties Show detailed information on DuplexDataManager drivers and services.

Help Open MMC's help facility.

4.2 Node DuplexWrite

MMC entry to manage DuplexWrite (not provided with MultiPath).

The result pane shows information on all DuplexWrite groups.

Status dependent icons

Normal

Open/Selected

Disabled

Recover

Error

CloneData

Disk is Offline

Disabled (hidden): A duplicate

signature was detected on a disk.

Action on DuplexWrite node (right mouse button)



Create... Create a new DuplexWrite group:

Dialog will display a list of all available non-DuplexWrite disks.

Select a disk and input the new DuplexWrite group name.

Select where the Configuration On Disk (COD) partition will physically be located on disk.

- DuplexWrite initializes the COD partition/blocks.

- The DuplexWrite group is now available and can be used.


On a system mirror (RootDisk) the RootDisk flag will be set automatically.



In MSCS installations shutdown the other node(s) first to avoid an inconsistent view of the storage resources.

The disk layout/partitioning must be suited for DuplexWrite. Otherwise, the command is rejected.

Set Recover Mode...

Mode to be used for recovery. Affects all DuplexWrite groups.

Verify: [default]

Read from both disks, compare and write if necessary (fast policy if

disks are slightly different).

Copy: Read from online disk and write to the second one (best policy if disks are completely different).

Delta: Recover only delta areas since failure (fastest policy if disks are slightly different).

Do not use Delta Recover when the disk to be recovered has been modified

externally since failure (e.g. by another server or by exchanging one disk of a RAID group).

Recover All... Recovers all DuplexWrite groups, which have status Error. A dialog displays two

options to start the process:

Immediate: [default]

Start process now.

Timer: Select date and time when the process should start. Process start time will be checked every 5 minutes, only.

Selectable if at least one piece of a DuplexWrite group has status Error.

Enable/Disable

Diskload Balancing

Set Dynamic Diskload Balancing On/Off. Affects all DuplexWrite groups.

On: Both disks of a DuplexWrite group are used for read. A special load balancing algorithm determines best disk to read from. The Prefer flag has no effect.

Off: No load balancing, read from preferred disk.

Delete CloneData tasks

Delete all CloneData inactive tasks and information.

Selectable if at least one CloneData task is available where CloneData is not active.

Prefer All... Prefer all DuplexWrite pieces with the same Unit Serial Number (assume one

storage). Not all storages support a unique Unit Serial Number for all drives (e.g. FibreCAT SX).

Disable All... Disable all DuplexWrite pieces with the same Unit Serial Number (assume one

storage). Not all storages support a unique Unit Serial Number for all drives (e.g. FibreCAT SX).



Enable/Disable

Autostart

Recover

Set Autostart Recover On/Off. Affects all DuplexWrite groups.

On: Every minute the status of all DuplexWrite groups will be checked. The

DuplexWrite status and the reason of the error piece will be checked. If it makes sense a recover will be started. This action is monitored and a start recover is limited to 3 tries per DuplexWrite group. At next system start this counter will be cleared.

In the case of a DuplexWrite missing piece - Online (one missing) or Online Error with corresponding reason a rescan will be started to get the lost device or the current status of the device.

In some cases a recover can not be started or make no sence. For this issue a resan make sense before a recover will be started.

A rescan started for DuplexWrite groups with a missing piece and DuplexWrite groups with an error piece and reason:

DW_REASON_READ_FAILED - Read error DW_REASON_WRITE_FAILED - Write error DW_REASON_WRITE_CONFIG_FAILED - COD could not be updated on

disk

DW_REASON_READ_CONFIG_FAILED - COD could not be reread DW_REASON_PNP_REMOVE - Plug and Play remove request caused

piece to be set to Error

A recover started for DuplexWrite groups with two pieces with Status Online Error and the Error piece with following reason:

DW_REASON_READ_FAILED - Read error DW_REASON_WRITE_FAILED - Write error DW_REASON_TIME_OUT_OF_SYNC - Piece disabled because timestamp

was older than that of the other one DW_REASON_WRITE_CONFIG_FAILED - COD could not be updated on

disk DW_REASON_READ_CONFIG_FAILED - COD could not be reread

DW_REASON_RECOVER_READ_FAILED - Data could not be read during recover process

DW_REASON_RECOVER_WRITE_FAILED - Data could not be written during recover process

DW_REASON_SIGNATURES_ARE_WRONG - Signatures of both pieces of the DuplexWrite group are not the same

DW_REASON_WRITE_FLAG - Data is inconsistent - COD could not be

synced after last write

No automatically recover started:

DuplexWrite status Error which is set by user will not processed. A recover is pending.

Off: [default] No Autostart Recover is enabled.

Properties Show detailed information on DuplexWrite.




Information on DuplexWrite group(s)

The DuplexWrite group data may not be up to date if the resource is owned by other cluster node (status Cluster).

Name DuplexWrite group name. This name can be chosen on group creation. The

associated MultiPath group IDs are optionally shown within brackets.

Additional attributes:

[root]: Selected group is prepared as RootDisk (RootDisk flag set).

(System): Selected group is system disk. System and boot disk must be the same.

(Boot): Selected group is boot disk. Not supported!

Group DuplexWrite group ID. Defined by DuplexWrite.

DWrite Size Effective size of the DuplexWrite group in Mbytes (including COD).

This size may be smaller than the disk's real size because of previous size adjustments to a smaller DuplexWrite group.

Recover Mode Mode to be used for recovery.

Verify: [default]

Read from both disks, compare, and write if necessary (fast policy if

disks are slightly different).


Delta: Recover only invalid areas since failure (fastest policy if disks are slightly different).

Copy (Delta):

In this case the recover mode is changed from Delta to Copy because the delta mode cannot be used (e.g. first recover or error during recover).

The recover mode is switched from Delta to Verify for the duration of the

recovery in cases where DuplexWrite knows that the differences between the pieces are minimal but where no delta information is available. This happens if COD could not be synced after last WRITE.

Settable in DuplexWrite Group

Diskload Balancing

Dynamic Diskload Balancing mode.


Off: [default] No load balancing, read from preferred disk.



-: No mode selected. Group is degraded and consists of only 1 piece.


Owner Owning cluster node of the resource.

<cluster node>: Cluster node name.

local: Local DuplexWrite group which is not used as cluster resource.

If no cluster service is running the owner is local.

This column is available in cluster environment only.

Drive Letter(s) Drive letters assigned to the disk partitions.

Action on selected DuplexWrite group (right mouse button)



Set Recover Mode...

Mode to be used for recovery. Affects selected DuplexWrite group.

Verify: [default]

Read from both disks, compare and write if necessary (fast policy if disks are slightly different).





Selectable only for Online DuplexWrite groups.

Enable/Disable

Diskload Balancing

Set Dynamic Diskload Balancing On/Off. Affects selected DuplexWrite group.

On: Both pieces of a DuplexWrite group are used for read. A special load balancing algorithm determines best piece to read from. The Prefer flag has no effect.

Off: [default] No load balancing, read from preferred piece.

To select the preferred disk, use menu action Prefer.

Reject Info Reject DuplexWrite group information (via Plug and Play).

Removing DuplexWrite group information only needed for maintenance in special

cases.



One case: If this cluster node blocks this resource due a fail over or move.

Please use this function with care!

Selectable only for DuplexWrite groups with status Cluster.

Rename Change DuplexWrite group name.

Status dependent actions:

Add... Add second disk (piece) to selected DuplexWrite group. Dialog will display a list

of all available disks. The selected one will be added as second piece to the

DuplexWrite group. The disk size must be equal or greater than first piece's size.



Selectable if the DuplexWrite group consists of one piece. The new disk status is Error. Start Recover to set the second piece online.

The second piece will set immediately online if the first piece is empty. A disk is

empty, if there is no any partition is available except the DuplexDataManager COD partition.

Delete Group Delete selected DuplexWrite group: clear disk's COD partition/blocks.

No user data will be affected. Use the SCSI view to administer non-DDM disks.


Selectable if the DuplexWrite group consists of one piece.

Resize Group Resize DuplexWrite group. If the DuplexWrite group was expanded, the new

added space will be recovered automatically. The minimum DuplexWrite size is

limited by the partitions available on the disk. If the COD position is at the end

of the mirrored space, it will be moved on resizing.

The minimum shrink/expand size is 39 MB (COD size).

Windows Server 2008 and newer: Resize DuplexWrite Group is not supported if

the Configuration On Disk (COD) partition is behind the system/data partition. By default only RootDisk mirrors are affected.

All other cluster nodes MUST be rebooted after resizing.

Selectable if all pieces are Online.

Properties Show detailed information on selected DuplexWrite group.




4.3 Node DuplexWrite Group

Displays the associated DuplexWrite pieces. The DuplexWrite group name and optional the MultiPath group ID are shown.

The result pane shows information on DuplexWrite group's disks.


Normal

Open/Selected

Disabled

Error

Recover

CloneData

Disk is Offline

Disabled (hidden): A duplicate signature was detected on a disk.

Action on DuplexWrite group node (right mouse button)



Set Recover Mode...

Mode to be used for recovery. Affects selected DuplexWrite group.

Verify: [default]

Read from both disks, compare and write if necessary (fast policy if disks are slightly different).


Delta: Recover only delta areas since failure (fastest policy if disks are slightly different).



Selectable only for Online DuplexWrite groups.

Enable/Disable

Diskload Balancing

Set Dynamic Diskload Balancing On/Off. Affects selected DuplexWrite group.

On: Both disks of the DuplexWrite group are used for read. A special load balancing algorithm determines best disk to read from. The Prefer flag has no effect.




To select the preferred disk, use menu action Prefer.

Reject Info Reject DuplexWrite group information (via Plug and Play).

Removing DuplexWrite group information only needed for maintenance in

special cases.

One case: If this cluster node blocks this resource due a fail over or move.

Please use this function with care!

Selectable only for DuplexWrite groups with status Cluster.

Rename Change DuplexWrite group name.


Add... Add second disk (piece) to selected DuplexWrite group. A dialog will display a

list of all available disks. The selected one will be added as second piece to the

DuplexWrite group. The disk size must be equal or greater than first piece's

size.



Selectable if the DuplexWrite group consists of one disk.

The new disk status is Error. Start Recover to set the second disk online.

The second piece will set immediately online if the first piece is empty. A disk is

empty, if there is no any partition is available except the DuplexDataManager COD partition.

Delete Group Delete selected DuplexWrite group: clear disk's COD partition/blocks.

No user data will be affected. Use the SCSI view to administer non-DDM disks.

In MSCS installations shutdown the other node(s) first to avoid an inconsistent view to the storage resources.

Selectable if the DuplexWrite group consists of one disk.

Resize Group Resize DuplexWrite group. If the DuplexWrite group was expanded, the new

added space will be recovered automatically. The minimum DuplexWrite size is

limited by the partitions available on the disk. If the COD position is at the end

of the mirrored space, it will be moved on resizing.

The minimum shrink / expand size is 39 MB (COD size).

Windows Server 2008 and newer: Resize DuplexWrite Group is not supported if

the Configuration On Disk (COD) partition is behind the system/data partition. By default only RootDisk mirrors are affected.

All other cluster nodes MUST be rebooted after resizing.



Selectable if all pieces are Online.



Information on DuplexWrite piece(s)

DWrite Status Disk's current DuplexWrite status.

SCSI bus related information:

Port Port identifier.

Path Sub-port identifier.

Target Target identifier (SCSI-ID).

LUN Device Logical Unit (SCSI-LUN).

Disk Disk number (physical device number) as defined by operating system.

MPath Group Associated MultiPath group ID (if applicable).

Unit Serial

Number

Unit Serial Number (if applicable).

LUN WWN Logical Unit Number (LUN) World Wide Name (WWN).

Only available for FibreCAT storage.

Model /

Connection Type

The storage model name and the connection type. e.g.: FibreCAT SX / iSCSI.

Host Bus

Adapter WWPN

Displays the Host Bus Adapter World Wide Port Name (WWPN), if available.

Controller/Port

WWPN

Displays the Controller/Port World Wide Port Name (WWPN), if available.

D_ID Destination Identifier: An address contained in a Fibre Channel frame that

identifies the destination of the frame. This ID displayed in the controller and

system BIOS for a boot lun. The D_ID viewed also as Device Port ID (QLogic)

and FC ID (Emulex).

Action on selected DuplexWrite piece (right mouse button)






Online Set selected disk (piece) online. The action depends on the state of the

corresponding DuplexWrite group:

The DuplexWrite group contains only one piece:

Set the status of the selected piece to Online. The DuplexWrite group will be accessible to the application, subsequently.

The DuplexWrite group consists of two pieces and the DuplexWrite status of both pieces is Error, or Disabled:

Set the status of the selected piece to Online. The DuplexWrite group will be accessible to the application, subsequently.

Be sure to select the most recently modified piece (flag Recent set). Open both pieces' Properties to get this information.

Selectable if status is Disabled or Error.

The new status is Online.

Recover... Recover selected disk: Copy back all data from other piece. A dialog displays

two options to start the process:

Immediate: [default] Start process now.

Timer: Select date and time when the process should start.

You might get this error message:

Start recover refused. This piece is the most resent one! See the online help for more information of this condition and search in the index for 'conserve'

In this case the following has happened:

The piece, which is in status error, is the more recent piece. Nevertheless it was set to error, because write commands were sent to the other piece, before the

more recent piece appeared. If both pieces were switched now, the file system could be corrupted. Therefore the more recent piece stays in status Error.

Because a recover would overwrite newer data, the recover is rejected in this case.

There are two possibilities now:

1. The data on the more recent piece should be overwritten: Disable the error piece and start recover.

2. The data on the more recent piece should be conserved:

If it is a system disk, the system has to be rebooted, while the first piece with older data must be disconnected. (disconnect LUN or change BIOS settings etc.) If it is a data disk, you can either reboot with disconnected older piece (see above) or follow these steps: Stop applications accessing this disk - remove drive letters - disable the online piece - set the error piece to online - start recover - reassign drive letters - start applications.



Selectable if status is Error, or Disabled. The other piece must be Online.

The new status is Recover, then Online.

Disable Disable selected disk. Useful to shutdown a disk, e.g. for maintenance reasons.

You might get this error message:

This piece is the most resent one! You are going to disable the conserved most recent piece.

If you proceed, this condition will be deleted.

See the online help for more information of this condition and search in the index for 'conserve'. To disable this piece, click Yes. To cancel this action, click No.

For more info see Recover...

Selectable if status is Online, or Error.

The new status is Disabled.

Delete Piece Delete selected disk (piece) from corresponding DuplexWrite group. The

(duplicate) disk signature is deleted.



Selectable if status is Error, or Disabled.

Delete Missing

Piece

Delete Missing entry on selected disk. This entry announces a second currently

not available disk - e.g. removed from system. The information on this disk is

read from selected disk's COD.


Selectable if Missing entry and status is Online, Error, or Disabled.

Prefer Prefer selected disk when reading data from corresponding DuplexWrite group.

This setting has no effect if Diskload Balancing mode is On.

Selectable if status is Online.

The new status is Online Preferred

Cancel Cancel recover process.

Selectable if status is Recover, Disabled (Recover pending), or Error (Recover pending).

The new status is Error.

CloneData... Copy (snapshot) a DuplexWrite disk to a second non-DuplexWrite disk. A dialog

will display a list of all available non-DuplexWrite disks whose capacity is

greater equal than the used size (up to last partition) of the disk to be copied.



Clone Data Destination Disk:

Select a destination disk from the list.

Clone Parameter:

Minimize time for which the group is degraded (disabled):

[default]

Select to disable the source after all blocks has been copied. The

modified blocks are copied again when the source is disabled. This

reduces DuplexWrite group's degradation time - with the disadvantage

of a non-predictable snapshot point in time

Start recover after CloneData succeeded: [default] Select to start recover automatically after CloneData succeeded.

Start recover in error case: [default]

Uncheck if status should be preserved in case of a CloneData error. If unchecked the DuplexWrite group remains in case of a CloneData error in the degraded mode.

Clone Time:

Immediate: [default] Select to start CloneData immediately.

Timer:

Setup date and time when CloneData task should start. The events Once, Daily, or Weekly can be chosen. Minimal time resolution is 5 minutes. DuplexWrite makes up to four attempts to start a scheduled CloneData task.

OK: Schedule/start the CloneData task.

The CloneData task will only be created if the destination disk has no partitions or the partitioning is exactly identical to the source disk (DuplexWrite group).

While CloneData is active the destination volumes (not at first time) will be locked. CloneData cannot start if a destination volume is in use.

Delete

CloneData

task

Delete scheduled CloneData task and all its information.

Selectable if CloneData is currently not active.

Cancel

CloneData

Cancel active CloneData task.

A canceled CloneData task (even a scheduled task) never starts again.

Cancel CloneData task will produce unexpected results on destination device (corrupt file system) if drive letters assigned to destination device before.

Selectable if CloneData is currently active.



Properties Show detailed information on selected disk.


4.4 Node MultiPath

MMC entry to manage MultiPath.

The result pane shows information on all MultiPath groups.


Normal

Open/Selected

Disabled/Pending Remove/Acknowledge needed

Error/Failed/Missing paths/Missing devices

Disk is Offline

Action on MultiPath node (right mouse button)



Enable/Disable

AutoRecovery

Set AutoRecovery mode On/Off. Affects all MultiPath groups.

On: [default]

If the MultiPath status was Error and the path has been repaired MultiPath will detect it and automatically reset the Error status.

Off: If the MultiPath status was Error and the path has been repaired

MultiPath will not reset the status. The path remains on status Error. It can be manually reset by menu action Clear Error.

Because a failing path remains on Error if AutoRecovery is disabled it should

always be enabled, except for maintenance.

Enable/Disable

AutoFailback

Set AutoFailback mode On/Off. Affects all MultiPath groups.

On: After error recovery MultiPath will automatically failback to the preferred path.

To select the preferred path, use menu action Prefer.

When AutoFailback is switched on AutoBalance will be switched off.

Off: [default] After error recovery MultiPath will not failback to the preferred path.

Don't use AutoFailback in MS Cluster Server configurations with contradictory



settings of preferred path.

This causes both nodes to failback to different paths/ports.

Enable/Disable

AutoBalance

Set AutoBalance mode On/Off. Affects all MultiPath groups.

On: The paths of the MultiPath groups will be automatically distributed across the available SCSI ports.

When AutoBalance is switched on AutoFailback will be switched off.

Off: [default] No automatic load balancing.

Not supported in Microsoft Cluster Server configuration.

Acknowledge

Configuration

Acknowledge current MultiPath configuration to monitor MultiPath path

configuration.

The current MultiPath path configuration will be stored in the registry and

compared periodical with the current configuration. Please acknowledge the configuration after the configuration is finished. DuplexWrite group created and in a pure MultiPath configuration the disks are initialized.

Note: In a Windows Server 2003 cluster environment move all resources to

any node and acknowledge the configuration on each node. The reason is the disk signature is needed for the check.

The monitor interval is 5 minutes per default and can be changed between 1 and 60 minutes via registry entry.

Check

Configuration Now

Compares the acknowledged/stored MultiPath path configuration with current

MultiPath configuration now.

Missing paths will logged in the system event log.

By default the MultiPath path configuration will be monitored / checked every 5 minutes.

Menu only available if the MultiPath configuration was acknowledged/stored before.

Clear Counters Clears the MPIO performance counters.

Menu only available if a supported MPIO DSM is installed.

Set Polling... MPIO poll setting. Enable only if installed MPIO DSM does not send events

due configuration (e.g.: losing a path) changes.

Enabled:

Two timers are settable:

Default poll interval (sec): Default poll interval in seconds if no snap-in is connected.

Poll interval if snap-in is connected (sec): Poll interval in seconds if snap-in is connected. This value is less than the default value and should view MPIO changes immediately.



A small value increases the system load.


Set

Timers/Counters...

MPIO global timers/counters setting.

Path Verify: Flag that indicating if automatic path verification must be performed every N seconds (where N depends on the value set in Path Verification Period).

Path Verification Period (sec): Timer for the periodicity path verification. The default is 30 seconds.

PDO Removed Period (sec): Timer for controls the amount of time that the pseudo-LUN will continue to be in memory, even after loosing all its paths. The default is 20 seconds.

Retry Count: Number of times a failed I/O will be retried if DSM Error Interpreter requests a retry. The default is set to 3.

Retry Interval (sec): Control interval of time after which a failed request is retried (after the DSM has decided so). The default is 1 second.


Properties Show MultiPath's default settings.


Information on MultiPath group(s)

The columns depend on DDM package and the connected storage model.

Name MultiPath group ID. The associated DuplexWrite group name is optionally

shown within brackets.

AutoRecovery MultiPath group specific AutoRecovery mode.

On: [default] If the MultiPath status was Error and the path has been repaired MultiPath will detect it and automatically reset the Error status.

Off: If the MultiPath status was Error and the path has been repaired MultiPath will not reset the status.

The path remains on status Error. It can be manually reset by menu action Clear Error.

Because a failing path remains on Error this mode should not be used, except for maintenance.

AutoFailback MultiPath group specific AutoFailback mode.

On: After error recovery MultiPath will automatically failback to the preferred

path. In FibreCAT SX MPIO DSM case it will automatically failback to the controller.






Don't use AutoFailback in MS Cluster Server configurations with contradictory settings of preferred path.

This causes both nodes to failback to different paths/ports.

AutoBalance AutoBalance mode for all MultiPath groups.

On: The paths of the MultiPath groups will be automatically distributed across the available SCSI ports.


Off: [default] No automatic load balancing.

Load Balance

Policy

MPIO Load Balance Policy.

Following MPIO Load Balance Policies are defined (defaults):

Fail Over Only - The fail over policy employs one active path and designates

all other paths as standby. The standby paths will be tried on a round-robin approach upon failure of the active path until an available path is found.

Round Robin - The round robin policy attempts to evenly distribute incoming requests to all processing paths.

Round Robin with Subset - The round robin with subset policy executes

the round robin policy only on paths designated as active. The standby paths will be tried on a round-robin approach upon failure of all active paths.

Dynamic Least Queue Depth - The least queue depth policy compensates

for uneven loads by distributing proportionately more I/O requests to lightly loaded processing paths.

Weighted Paths - The weighted paths policy allows the user to specify the

relative processing load of each path. A large number means that the path priority is low.

Least Blocks - The least blocks policy routes requests to the processing path with the least number of pending I/O blocks.

Only available if a supported MPIO DSM is installed.

DSM Name MPIO Device Specific Module (DSM) Name.

Friendly name of the DSM controlling the device.




Port Group Port group ID. All devices, which have at least one common port, form a port

group.

In MPIO case this info is not available.

Unit Serial Number Unit Serial Number (if applicable).



Model / Connection

Type


Drive Letter(s) On the disk partitions/volumes assigned drive letters.

Action on selected MultiPath group (right mouse button)



Enable/Disable

AutoRecovery

Set MultiPath group specific AutoRecovery mode On/Off.

After reboot this setting will be lost and the global setting applied, instead.

On: [default]


Off: If the MultiPath status was Error and the path has been repaired MultiPath will not reset the status. The path remains on status Error. It can be manually reset by menu action Clear Error.

Because a failing path remains on Error this mode should not be used, except for maintenance.

Enable/Disable

AutoFailback

Set MultiPath group specific AutoFailback mode On/Off.


path.



Selectable if AutoBalance is off.

MPIO: Only supported for Load Balance Policy Fail Over Only.

Don't use AutoFailback in MS Cluster Server configurations with contra

dictionary settings of preferred path. This causes both nodes to failback to different paths/ports.

Set Load Balance Set MPIO Load Balance Policy.



Policy Following MPIO Load Balance Policies are defined (defaults):

- Fail Over Only

- Round Robin - Round Robin with Subset - Dynamic Least Queue Depth - Weighted Paths - Least Blocks

In Microsoft cluster environment the Load Balance Policy may affect the cluster failover behavior.


Properties Show detailed information on selected MultiPath group




4.5 Node MultiPath Group

Displays the associated paths.

The result pane shows information on MultiPath group's paths.


Normal

Open/Selected

Disabled/Pending Remove

Error/ Failed

Disk is Offline

Action on MultiPath group node (right mouse button)



Enable/Disable

AutoRecovery

Set MultiPath group specific AutoRecovery mode On/Off.

After reboot this setting will be lost and the global setting applied, instead.

On: [default]


Off: If the MultiPath status was Error and the path has been repaired MultiPath will not reset the status. The path remains on status Error. It can be manually reset by menu action Clear Error.

Because a failing path remains on Error if AutoRecovery is disabled it should always be enabled, except for maintenance.

Enable/Disable

AutoFailback

Set MultiPath group specific AutoFailback mode On/Off.


path. In FibreCAT SX MPIO DSM case it will automatically failback to the controller.



Selectable if AutoBalance is off.



MPIO: Only supported for Load Balance Policy Fail Over Only.

Don't use AutoFailback in MS Cluster Server configurations with contradictionary

settings of preferred path. This causes both nodes to failback to different paths/ports.

Set Load

Balance Policy

Set MPIO Load Balance Policy.

Following MPIO Load Balance Policies are defined (defaults):

- Fail Over Only

- Round Robin - Round Robin with Subset - Dynamic Least Queue Depth - Weighted Paths - Least Blocks

In Microsoft cluster environment the Load Balance Policy may affect the cluster failover behavior.




Information on path(s)

The columns depend on DDM package and the connected storage model.

MPath Status Path's current MultiPath status.






Disk Disk number (physical device number) as defined by operating system.

DWrite Name Associated DuplexWrite group name (if applicable).

Storage

Controller/Port

Displays the controller number to the storage of this MultiPath path. The

representation for the FibreCAT family is SP A or SP B. The representation for all

other storage (S60/S80) is a zero based digit.

MSCS configurations: If the device is assigned to another node this info is not available.

Weight The value that determines which path the Device Specific Module (DSM) picks if

the Load Balance Policy is 'Weighted Paths'.




Host Bus

Adapter WWPN


Controller/Port

WWPN


Path Identifier Displays the MPIO Path Identifier. Unique identifier to distinguish paths known to

the Device Specific Module (DSM).



identifies the destination of the frame. This ID displayed in the controller and

system BIOS for a boot lun. The D_ID viewed also as Device Port ID (QLogic)

and FC ID (Emulex).

Action on selected path (right mouse button)




Activate Activate selected path. All alternative paths will be set to Standby.

Selectable if status is Standby.

The new status is Active.

In MPIO case and Load Balance Policy 'Round Robin with Subset' more than one path may in status Standby.

Disable Disable selected path. Useful to switch off a path, e. g. for maintenance reasons.

Be sure that an alternative path is available (Active, or Standby). Otherwise, you will disrupt the connected device!

Selectable if status is Active, Standby, or Error.

The new status is Disabled.

Not supported in MPIO case.

Enable Enable selected path.

Selectable if status is Disabled.

The new status is Active, or Standby, depending on the AutoFailback mode and Preferred setting.


Clear Error Enable selected path. The Error status will be cleared - if possible.



Selectable if status is Error.

The new status is Active, or Standby, depending on the AutoFailback mode and Preferred setting.

In MPIO case the status is described as Failed. Clear Error only supported for FibreCAT SX60/SX80/SX88/SX100 at this time. The new status is Standby.

Prefer Prefer selected path: This path will be preferably set Active by MultiPath.

Depending on the AutoRecovery and AutoFailback modes MultiPath will re-

activate this path 'on the fly' - e.g. after error recovery - or on reboot.

Selectable if status is Active, or Standby.

The new status is Active Preferred, or Standby Preferred, respectively.


Properties Show detailed information on selected path.




4.6 Node SCSI view

The result pane lists all SCSI ports.


Normal

Open/Selected



Action on SCSI View node (right mouse button)



Reset plug and play

info

Reset plug and play information for all ports.


Information on port

Name Port identifier.

Driver Driver name.

DDM Mode Available DDM functionality: (none), MultiPath, DuplexWrite, DDM

(=both), MPIO

Host Bus Adapter

WWPN


Action on selected port (right mouse button)



Enable/Disable

DuplexWrite

Enable/disable selected port for DuplexWrite functionality. This option can

be used for ports never be used with DuplexWrite.

Enable only DuplexDataManager released ports/controller. Otherwise you work on your own risk.



The setting will be in effect after the next reboot.

Not selectable if a disk at this port is member of a DuplexWrite group with more than one piece.

Enable/Disable

MultiPath

Enable/disable selected port for MultiPath functionality. This option can be

used for ports never be used with MultiPath.


Never operate a redundant MultiPath connection without MultiPath functionality. This may result in data corruptions!

By default only released drivers/ports are enabled for MultiPath.


Enable/Disable

DuplexDataManager

Enable/disable selected port for MultiPath and DuplexWrite functionality.

The DDM filter driver is removed from port's I/O stack. This option can be

used in suspicious debugging situations, or for ports never be used with

DDM.



By default only released drivers/ports are enabled.


In MPIO case no Enable/Disable DuplexDataManager is supported. In this

case all device inquires which listed in the INF-File due installation of the Device-Specific Module (DSM) are enabled for MPIO.


Properties Show detailed information on selected port.




4.7 Node SCSI port

Represents a host bus adapter or a channel (sub-port) of a host bus adapter.

The result pane lists all connected devices.


Normal

Open/Selected



Action on SCSI port node (right mouse button)



Enable/Disable

DuplexWrite

Enable/disable selected port for DuplexWrite functionality. This option can

be used for ports never be used with DuplexWrite.




Enable/Disable

MultiPath

Enable/disable selected port for MultiPath functionality. This option can be

used for ports never be used with MultiPath.



By default only released drivers/ports are enabled for MP.


Enable/Disable

DuplexDataManager

Enable/disable selected port for MultiPath and DuplexWrite functionality.

The DDM filter driver is removed from port's I/O stack. This option can be

used in suspicious debugging situations, or for ports never be used with

DDM.





By default only released drivers/ports are enabled.


In MPIO case no Enable/Disable DuplexDataManager is supported. In this

case all device inquires which listed in the INF-File due installation of the Device-Specific Module (DSM) are enabled for MPIO.


Properties Show detailed information on selected port.


Information on device

Device Type Device Type according SCSI specification, possible values:

Disk, Tape, Printer, Processor, WORM, CD-ROM, Scanner, Optical Disk,

Jukebox, Network, Unit Not Present, Unknown Type <0x??>


Port Port identifier

Path Sub-port identifier

Target Target identifier (SCSI-ID)

LUN Device Logical Unit (SCSI-LUN)

Disk Disk number (physical device number) as defined by operating system

DDM Mode Available DDM functionality: (none), MultiPath, DuplexWrite, DDM

(=both), MPIO

Unit Serial Number Unit Serial Number (if applicable).



Model / Connection

Type

The storage model name and the connection type. e.g.: FibreCAT SX /

iSCSI.

Controller/Port Displays the Controller/Port World Wide Port Name (WWPN), if available.



WWPN


identifies the destination of the frame. This ID displayed in the controller

and system BIOS for a boot lun. The D_ID viewed also as Device Port ID

(QLogic) and FC ID (Emulex).

Action on selected device (right mouse button)



Create... Create a new DuplexWrite group based on selected disk:

Dialog will show up to enter the new DuplexWrite group name.

Select where the Configuration On Disk (COD) partition will

physically be located on disk.

DuplexWrite initializes the COD partition/blocks.

The DuplexWrite group is now available and can be used.


On a system mirror (RootDisk) the RootDisk flag will be set automatically.


Disk's layout/partitioning must be suited for DuplexWrite. Otherwise, the command is rejected.

Enable Disk Enable disk for use.

To enable this disk the signature will be deleted.

Disk is disabled (hidden) because a duplicate signature was found on disk.

Properties Show detailed information on selected device.




5 DuplexDataManager Status

5.1 DuplexWrite Status

Icon DuplexWrite Status

Online Disk is online, preferred for read.

Online Disk is online, not used for read.

Online Disk is online, Dynamic Diskload Balancing enabled.

Error Disk is offline due to an error condition.

Recover Disk is recovering data from other piece.

Disabled Disk has been set inactive, e.g. for maintenance reasons.

Cluster Disk is used by other MS cluster node.

Additional Attributes

Preferred Disk is preferred for read.

(one missing) Entry announces a second currently not available disk - e.g. removed from

system. The information on this disk is drawn from selected disk's COD.

(synced) Disk has been disabled in sync (data flushed) and can be used as data

snapshot.

(Recover

pending)

Disk is marked for deferred Recover. The process start time can be read from

DuplexWrite Piece's property sheet. DuplexWrite check the start time in 5

minutes interval.

(most recent) Both pieces of the DuplexWrite group are Error or Disabled. This piece is the

most recent piece.

Attributes used for CloneData

(CloneData scheduled) CloneData task scheduled, but not active.

(CloneData canceled) CloneData task was canceled.

(CloneData x%) CloneData currently active (progress indicated).

(CloneData finished) CloneData task successfully finished.

(CloneData error) CloneData task terminated with an error.



5.2 MultiPath Status

Icon MultiPath Status

Active Active path; as chosen by user.

Standby Standby path; as chosen by user.

Error An error has occurred on this path.

Disabled Path has been set inactive, e.g. for maintenance reasons.

Additional Attributes

Preferred Path is preferred for I/O.

Removed Path to device is removed (Plug and Play surprise removal).

Icon MPIO Status

Active Active path; as chosen by user.

Standby/ Passive

Standby/Passive path; as chosen by user.

Failed An error has occurred on this path.

Pending Remove

Path to device is pending to remove.

Removed Path to device is removed.

6 Property sheets

6.1 DuplexDataManager

Tab: About

Information about DDM.

Tab: Snap-in

Information about DDMs snap-in module.

Tab: Driver



Information about DDMs driver module.

Driver status

Tab: Service

Information about DDMs service module.

Service settings

Tab: Cluster Support

Information about DDMs cluster service module.

Cluster service status

Tab: SNMP Agent

Information about DDMs SNMP agent.

Tab: System Tray

Information about the System Tray.

Following information only available with MultiPath MPIO:

Tab: Fujitsu DSM SX60/SX80/SX88/SX100

Information about the Fujitsu Technology Solutions device specific module (DSM) for the FibreCAT SX60/SX80/SX88/SX100 (hilmpfsc.sys).

Tab: Support Bus Driver

Information about the Multipath Bus Driver (mpio.sys).

Tab: Device Driver

Information about the Multipath SCSI Disk Filter Driver (mpdev.sys).

Tab: Scsi Filter Driver

Information about the Multipath Port-Driver Filter Driver (mpspfltr.sys).



6.2 DuplexWrite

Tab: DuplexWrite Settings

Default Settings

Recover

Mode

Default mode to be used for recovery. Initial setting for new DuplexWrite group.

Values: Verify [default], Copy, Delta

Settable in DuplexWrite

Diskload

Balancing

Default for Dynamic Diskload Balancing. Initial setting for new DuplexWrite group.

Values: On, Off [default]


Autostart

Recover

Setting for Autostart Recover.



6.3 DuplexWrite Group

Tab: DuplexWrite Group

DWrite Group

The DuplexWrite group data may not be up to date if the resource is owned by other cluster node (status Cluster).

Name This name can be chosen on group creation. The associated MultiPath group IDs

are optionally shown within brackets.

Additional attributes:

[root]: Selected group is prepared as RootDisk (RootDisk flag set).

(System): Selected group is system disk. System and boot disk must be the same.

(Boot): Selected group is boot disk. Not supported!

Settable in DuplexWrite Group.


DWrite Size Effective size of the DuplexWrite group including COD.



This size may be smaller than the disk's real size because of previous size adjustments to a smaller DuplexWrite group.

Key Unique key (signature) to identify the disks which form a DuplexWrite group. Defined by DuplexWrite, stored on COD.

Pieces

found

Number of disks (pieces) found which belong to the current DuplexWrite group.

Should be 2 of 2.

RootDisk This flag indicates DuplexWrite to handle the current DuplexWrite group as

RootDisk (system/boot disk).



Recover

Mode

Mode to be used for recovery.

Verify: [default]

Read from both disks, compare, and write if necessary (fast policy if disks are slightly different).



Copy (Delta): In this case the recover mode is changed from Delta to Copy

because the delta mode cannot be used (e.g. first recover or error during recover).

The recover mode is switched from Delta to Verify for the duration of the recovery

in cases where DuplexWrite knows that the differences between the pieces are minimal but where no delta information is available. This happens if COD could not be synced after last WRITE.


Diskload

Balancing

Dynamic Diskload Balancing mode.



-: No mode selected. Group is degraded and consists of only 1 piece.


Disk Status Displays the status of the disk.

Online: The disk is online.

Offline: The disk is offline.



Cluster: The cluster resource (disk) is owned by an other cluster node.

Not supported: This info is not supported.

In the Disk Management the status Online/Offline is changeable.

In special cases, DDM is unable to access the cluster resources. In this case the

status Offline is displayed in contrast to Reserved in the Disk Management. One

reason: The disk is not initialized.

This info is supported with Windows Server 2008.

Virtual Device Address





Cluster

Node Cluster node name that currently owns the resource.

Resource Cluster resource name of the disk resource.

6.4 DuplexWrite Piece

Tab: DuplexWrite Piece

DWrite Group

Name DuplexWrite group name.



Piece Pieces internal ID. Defined by DuplexWrite.

Disk Disk number. Defined by operating system.

DWrite Piece

Status Disk's current DuplexWrite status.

Maintained in DuplexWrite Group

<message> Detailed status information, e.g. error reason, or recovery progress.

If the piece is Online the displayed information is the reason which associated with

the last change to a degraded status. During recovery the recover progress count

is displayed.



Flags Further flags, e.g.:

Forced: (internal)

Hidden: (internal) Recent: Most recently updated piece.

If both pieces of a DuplexWrite group are on Error select that with flag Recent set.

MPath

Group

Associated MultiPath group ID (if applicable). Defined by MultiPath.

Tab: MPath

DWrite Group





MPath Group

Group MultiPath group ID. Defined by MultiPath.


Paths to this

Disk

List of all paths to current piece. MultiPath status and SCSI bus related information

are shown.

Maintained in MultiPath Group

Tab: Device


<inquiry> Device's SCSI inquiry string.

<model /

connection

type>


Device Type Device Type according SCSI specification.

Device Address


Path Path identifier





Disk Properties


Write Cache Displays Write Cache setting on the disk. This setting improves disk performance,

but a power outage or equipment failure might result in data loss or corruption.

Values: Enabled, Disabled, and Unknown

To modify Write Cache setting start Computer Management selects the corresponding disk device in the Device Manager.

Modification of Write Cache settings will displayed at next reboot, restart of

DuplexDataManager service, Rescan devices in the DuplexDataManager, or Rescan Disks in the Disk Management snap-in.

Capacity Disk's real capacity.

Signature Disk's signature. Defined by operating system.

Unit Serial

Number




Volumes

contained

on this Disk

List of all volumes (partitions) defined for the current disk. Volume label, drive

letters, and capacity are shown.

Tab: CloneData

Source DWrite Group









Destination Device








Clone Data

Parameter CloneData's parameter. Possible values:

Minimize time for which the group is degraded Start recover after CloneData succeeded Start recover in error case


Time Information of the mode (Once/Daily/Weekly) and the (next scheduled) start time

of the CloneData task.


Status The current status of the CloneData task. Possible values:

Scheduled: task scheduled, but not active

Canceled: task was canceled CloneData: currently active (progress indicated) Finished: task successfully finished Error: task terminated with an error

Tab: Debug

Internal information for maintenance and debugging.

6.5 MultiPath

Tab: MultiPath Defaults

Default Settings

AutoRecovery Default AutoRecovery mode. Initial setting for new MultiPath group.

Values: On [default], Off

Settable in MultiPath

AutoFailback Default AutoFailback mode. Initial setting for new MultiPath group.






AutoBalance Default AutoBalance mode. Initial setting for new MultiPath group.

Values: On, Off [default], Unsupported



MPIO Timers/Counters

Timers/Counters are MPIO global defaults.

Path Verify The flag that indicating if automatic path verification must be performed every N

seconds (where N depends on the value set in Path Verification Period).

Values: Enabled, Disabled

Path

Verification

Period

The timer for the periodicity path verification. The default is 30 seconds.

PDO

Removed

Period

The timer for controls the amount of time that the pseudo-LUN will continue to be

in memory, even after loosing all its paths. The default is 20 seconds.

Retry Count The number of times a failed I/O will be retried if DSM Error Interpreter requests a

retry. The default is set to 3

Retry

Interval

The control interval of time after which a failed request is retried (after the DSM

has decided so). The default is 1 second.

Tab: Performance

Displays the current MultiPath transactions (IOs per second). One row relates to one MultiPath

group. Per MultiPath group the columns show the address of the MultiPath path, the current and

the average percentage of the port group.

# MultiPath group ID.

LUN Device Address <Port identifier>/<Path identifier>/<Target identifier>/<Device

Logical Unit>

Current Current percentage transaction on this path.

Average Average percentage transaction on this path.

...



6.6 MultiPath Group

Tab: MultiPath Group

MPath Group


DWrite Name DuplexWrite group name.


AutoRecovery AutoRecovery mode.

Values: On [default], Off

Settable in MultiPath Group.

AutoFailback AutoFailback mode.



Port Group Port group ID. All devices which have at least one common port form a port group. Defined by MultiPath.











Cluster



Tab: MPIO Group (only for MPIO)



MPIO Group

MPIO Group MPIO disks group name. Defined by MPIO.

DWrite

Name

DuplexWrite group name (if available).


Used Serial Used device identification to find multiple paths (Unit Serial Number (USN) or Lun

World Wide Name (WWN)).

Disk Id MPIO unique disk / device identifier.

DSM Name Vendor of the Device Specific Module (DSM) for this MPIO group.

Instance MPIO instance.

Load

Balance

Policy

Following MPIO Load Balance Policies are defined (defaults): Fail Over Only

Round Robin Round Robin with Subset Dynamic Least Queue Depth Weighted Paths Least Blocks

AutoFailback AutoFailback mode.


Note: Only supported for Load Balance Policy Fail Over Only.


Cluster



Tab: Configuration (only for MPIO)

Controller Configuration

DSM Name Vendor of the Device Specific Module (DSM) for this MPIO group.

Identifier

Type

Controller identifier type in hexadecimal presentation.

Identifier Controller identifier in hexadecimal presentation.

Controller

State

Controller state in hexadecimal presentation.



6.7 MultiPath Path

Tab: MultiPath Path

MPath Group



MPath Path

Status Path's current MultiPath status MultiPath status.

MSCS configurations: If the device is assigned to another node the status might be incorrect.

Maintained in MultiPath Group.

Storage

Controller

Displays the controller number to the storage of this MultiPath path. The

representation for the FibreCAT family is SP A or SP B. The representation for

all other storage (S60/S80) is a zero based digit.


Storage Port Displays the port number (zero based) to the storage of this MultiPath path.


Host Bus

Adapter WWPN


Controller/Port

WWPN


Tab: MPIO Path (only for MPIO)

MPIO Group

MPIO Group MPIO disks group name. Defined by MPIO.


MPIO Path

Status Path's current MultiPath status.

MSCS configurations: If the device is assigned to another node the status might be incorrect.




Path Identifier The MPIO Path Identifier. Unique identifier to distinguish paths known to the

Device Specific Module (DSM).

Path Weight The value that determines which path the Device Specific Module (DSM) picks if

the Load Balance Policy is 'Weighted Paths'.

Primary Path The flag to indicate if this is a primary path. Values: 0 - not primary path, 1 -

primary path.

Storage

Controller

The storage controller number (zero based) where this path is connected. In

FibreCAT case controller number 0 is assigned SP A.

Storage Port The storage port number (zero based) where this path is connected.

Host Bus

Adapter WWPN


Controller/Port

WWPN


Tab: Device



<model /

connection

type>


Device Type Device Type according SCSI specification.

Device Address





Disk Properties


Write Cache Displays Write Cache setting on the disk. This setting improves disk

performance, but a power outage or equipment failure might result in data loss

or corruption.


To modify Write Cache setting start Computer Management select the corresponding disk device in the Device Manager.



Modification of Write Cache settings will displayed at next reboot, restart of

DuplexDataManager service, Rescan devices in the DuplexDataManager, or Rescan Disks in the Disk Management snap-in.



Unit Serial

Number




Volumes

contained on

this Disk



Tab: Debug

Internal information for maintenance and debugging.

6.8 SCSI Port

Tab: Port

Information on port

<descript> Host bus adapter description.

Port Port identifier. Defined by operating system.

Driver Driver name.

Location PCI bus specific information: bus, device, and function number.

DDM Mode Available DDM functionality. Initial setting by DDM according to port's properties.

Values: disabled, MultiPath, DuplexWrite, DuplexDataManager (=both)

Controller

Info

Additional controller info, if available (e.g. LIP Reset Count).

Current Emulex HBA API library information (Windows Server 2003):

Windows Server 2008: The Microsoft HBA API (hbaapi.dll) is used.

If the Microsoft HBA API has been installed (typically with SP1 or SP2),

Emulex does not install the Emulex HBA API (emulexhbaapi.dll). In this



case, the Microsoft HBA API (hbaapi.dll) is used.

If the Microsoft HBA API has not been installed (typically pre-SP1), Emulex will install the Emulex HBA API in the system folder. If the server is later upgraded to SP1or later, the Microsoft HBA API will replace the Emulex HBA API.

Current QLogic HBA API library information:

QLogic installs the QLogic HBA API Library (ql2xhai2.dll) for HBA API access.

In other cases the appropriate SNIA HBAAPI of the selected controller must installed.

In addition the Microsoft command line tool fcinfo.exe (Microsoft Download) can be

installed. Tool for gathering configuration information on your Fibre Channel SAN based on the SNIA HBAAPI for management of Fibre Channel Host Bus Adapters and

discovery of SAN resources. For more info on HBAAPI, see: http://www.snia.org/tech_activities/hba_api

Tab: PnP

Information on Plug and Play activities

Removed

Devices

List all devices (port/path/target/lun/signature/time) that were removed via

Plug and Play manager since last reboot or reset from DDM user interface.

With this information you can reconstruct former MultiPath configuration.

http://www.snia.org/tech_activities/hba_api



6.9 SCSI Device

Tab: Device



<model /

connection

type>


Device

Type

Device Type according SCSI specification.











Device Address

Real Real device address (port/path/target/lun)

Virtual Virtual device address (port/path/target/lun)

Disk Properties


Write

Cache

Displays Write Cache setting on the disk. This setting improves disk performance,

but a power outage or equipment failure might result in data loss or corruption.


To modify Write Cache setting start Computer Management selects the corresponding disk device in the Device Manager.

Modification of Write Cache settings will displayed at next reboot, restart of DuplexDataManager service, Rescan devices in the DuplexDataManager, or Rescan Disks in the Disk Management snap-in.





Unit Serial

Number




Volumes

contained

on this Disk



Tab: DuplexDataManager

General Information on DDM mode.

DuplexWrite



DWrite

Status

The Disk current DuplexWrite status.

Maintained in DuplexWrite Group.

MultiPath


MPath

Status

The path current MultiPath status.

Maintained in MultiPath Group

MPIO

MPIO Disk MPIO disks group name. Defined by MPIO.

MPath

Status

The path current MultiPath status.




Tab: CloneData

Source DWrite Group









7 Technical Info

7.1 How to find different paths to one disk

To find out if multiple paths exist to a disk the driver compares the devices serial number

and LUN for all paths.

MultiPath only supports storage which returns a proper device serial number (Unit Serial

Number) in INQUIRY page 0x80.

You must not configure a logical drive in a way that the same drive shows up with

different LUN numbers.

7.2 How to find a DuplexWrite group

DuplexWrite stores the mirroring information in the COD (Configuration On Disk). This

COD contains all DuplexWrite group relevant information. The COD of a DuplexWrite

group has a unique key. By interpreting the COD the driver finds the disks of the

DuplexWrite groups at boot time or if a new disk (mirror) appears with a plug and play event.

7.3 System / Boot Partition

For the Windows boot process we distinguish:

System Partition The system partition refers to the disk volume that contains the

hardware-specific files that are needed to start Windows (for

example, Ntldr, Boot.ini, and Ntdetect.com).

The system partition can, but is not required, to be the same

partition as the boot partition.

Boot Partition The boot partition refers to the disk volume that contains the

Windows operating system files (by default, in the WINDOWS

folder) and its support files (by default in the

WINDOWS\System32 folder).

The boot partition can, but is not required, to be the same

partition as the system partition.

There will be one (and only one) System partition, but there will

be one Boot partition for each operating system in a multi-boot

system.

In DuplexDataManager the system/boot DuplexWrite group disks is named RootDisk. This group is featured with '[root]' in the MMC snap-in.

In a mirrored RootDisk configuration system/boot disk must be the same.



7.4 COD Partition

Each DuplexWrite disk has to be partitioned into the COD (Configuration On Disk) data

area and the user partitions. In DuplexDataManager case the COD area is a non-standard

primary partition to be used by DuplexWrite. It contains DuplexWrite configuration and state data, as well as information on partner disk, last time updated, and host's name.

DuplexWrite supports Basic Disks, only. GUID partition table (GPT) Disks and Dynamic

Disks are not supported.

The COD partition uses a free primary partition on disk/LUN. The size of this partition is

at least 32 MB. It is seen as 'Healthy' without label and drive letter in Disk Management, as shown in the example below:

By default DuplexDataManager creates the COD at the beginning of mirrored space. In

the case of RootDisk (system/boot partition) the COD will be created at end of mirrored space.

The partition size is aligned according to disk's geometry and thus can be larger than

COD's minimal space requirement of 32 MB. We recommend 39 MB as minimum.

primergy duplexdatamanager help - fujitsu...

Documents