EMC DMX LUN Presentation Procedure This procedure provides the basic guidelines for creating a new LUN on a DMX array controller, presenting the new LUN to a host and (for Solaris) configuring the host to use the new LUN. LUN Presentation - DMX Required Steps Typical steps for LUN creation on DMX are:

Device Creation/Configuration - This includes standard devices and meta devices

Device Mapping - Presenting the device to a front end port. Device Masking - Restricting access to the device/LUN to a

specific HBA (or set of HBAs). DMX Device Creation/Configuration The EMC DMX line of arrays currently support SCSI-3 drives that are FC. Drive sizes currently on site include 300GB FC 10K, 146GB FC 15K, and 146GB FC 10K. Drive installation is performed by EMC. Physical drives in the DMX are split into slices/hypers. Currently, 5.66GB and 13.62GB hyper sizes are the standard. Hypers typically have a protection associated with them. Currently RAID1/Mirror and RAID5(7+1) are the two protection levels being used on DMX storage. These hypers become the presented devices/LUNs. When disk drives are installed, EMC works with the customer to develop a default hyper/slice layout for the disk drives.

Note: While it is possible to remove and create hypers/devices in the DMX array for the purposes of resizing, moving or re-arranging the layout of the array, this type of activity is not recommened. Performance and optimization layouts can be adversely affected by this type of operation. If this type of activity is required, it is best to work with EMC and have them perform any necessary work associated with the activity.

It is possible to merge hypers together to create a meta device for the purpose of presenting units/LUNs larger than the standard 5.66GB or 13.62GB LUNs. The current standard is to only create 4 or 8 device (call 4-way or 8-way) metas. Creating a meta with more than 8 hypers can create a performance issue due to the way back-end disks are connected to the DMX.

To create a meta device using EMC Control Center, use the following steps:

Right-click on the DMX array and select Configure -> Meta Device Configuration... (See Figure1).

The Meta Device Configuration screen appears (See Figure2).

Expand the Unmapped Standard device folder in the left-hand

pane and select the devices to include in the meta (See Figure3). It is recommended that the devices selected be in numberic order. This will assure that the load on the back-end is evenly distributed. (Note: Take care when selecting the devices to include in the meta so that a performance issue is not created).

In the right-hand pane, click on/highlight the Striped Metas folder. (Note: Concatenated Metas are considered obsolete and should never be used. There can be significant performance issues for a LUN built with concatenated metas).

Click on the Create Meta button to create the meta device. Expand the right-hand pane Striped Metas folder and locate the

new meta. The name/identifier for the meta will be the name/id of the first devices added as a member of the meta device. Verify that all devices have been included in the meta device to create.

Click on the Continue button to review the proposed meta device creation (See Figure4).

Review the meta information and click on Execute and then on Yes to finish the meta device creation.

Device Mapping Device mapping is the process of presenting a device (either a standard hyper device or a meta device) to a front-end port on the DMX. At a minimum, a device is presented to two front-end ports. As a standard, the sum of the port numbers used to present the device should total 17 (rule of 17). If a device is presented on port 11A-1, then the device would also be presented on port 6A-1.

To map a DMX device using EMC Control Center, use the following steps:

Right-click on the DMX array and select Configuration -> SDR Device Mapping... (See Figure5).

A lock will be acquired on the array and a confirmation screen will have to be acknowledged in order to proceed with the device mapping. Click on the Yes button to continue.

The SDR Device Mapping screen will be displayed (See Figure6).

In the left-hand pane, expand the Unmapped Devices folder and select the device to map.

In the right-hand pane, expand the Host Directors and the actual director to be used so that a port on the director can be highlighted/selected.

Click on the Move button to map the device to the first port. Acknowledge the warning message by clicking on OK.

To map the device to the other port, expand the Host Directors folder in the left-hand pane and the actual director that the device was mapped to.

Continue to expand down the tree until the mapped device is located (See Figure7).

Once located, select/highlight the mapped device. In the right-hand pane, expand the secondary port for the device

down to the port to present the device on. Highlight/select the port and then click on the Copy button to

map the device to the second port. Acknowledge the warning message by clicking on OK. Click on Continue to call up the confirmation screen (See

Figure8).

Review the settings and click on Execute to map the device to the selected front-end ports. (Note: Verify that the Address at Target value for the device is the same on each port. If they are not, edit the entries to make them the same).

It will take several minutes to complete the mapping operation. Device Masking Device masking allows the access to a particular LUN on a DMX front-end port to be controlled down to the HBA level. This allows for multiple hosts to share front-end DMX ports without both hosts having access to the same LUNs and creating a potential problem.

To set the masking on a device to allow a host access using EMC Control Center, perform the following steps:

Expand the Hosts folder in EMC Control Center and continue to expand the tree until an HBA WWN can be selected (See Figure9).

Right-click on the WWN and select Masking -> Modify Masking Configurations....

This will call up the Modify Masking Configurations screen (See Figure10).

Working across the screen from left to right, top to bottom, select the array with the device to allow the host access to.

Check the port/controller that the device was mapped to. Change the Select Type of Device dropdown to All Devices

and then click on the Show Devices button. Locate the device to mask in the bottom box and check the

device. Click on the Grant button to give the HBA/host combination

access to the device. Repeat this process for the other HBA (the currently uncheck one

in the upper left-hand box). Start by unchecking the current HBA and checking the other HBA.

When all grants have been completed, click on the Continue button.

The Modify Masking Configuration - Preview Changes screen will be displayed (See Figure11).

Review the changes to be made to the masking and click on the Edit Changes button to make corrections.

To continue the masking operation, check the Activate the VCMDB checkbox.

Click on the Execute button to complete the masking operation. LUN Presentation - Host (Solaris) Required Steps Once the LUN has been created and presented on the DMX array, there are some configuration steps that are required on the host. Depending on the version of Solaris and the HBA in use, those steps will vary but typically come down to configuring the HBA, configuring the binding (persistent or dynamic) and editing /kernel/drv/sd.conf. After these configuration steps are complete, a reboot of the host is necessary to see the storage in most cases.