dellcert - powervault training
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DellCert - PowerVault TrainingTRANSCRIPT
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Dell PowerVault Storage and Backup Solutions
Contents General Information ..................................................................................................................................... 6
Dell PowerVault™ Storage and Backup Solutions ..................................................................................... 6
Objectives.................................................................................................................................................. 6
Course Contents ........................................................................................................................................ 6
Introduction .................................................................................................................................................. 7
Objectives.................................................................................................................................................. 7
PowerVault Product Lines ......................................................................................................................... 7
Terms and Concepts .................................................................................................................................. 7
iSCSI ....................................................................................................................................................... 7
Network Attached Storage (NAS) ......................................................................................................... 8
PowerEdge™ RAID Controller (PERC) .................................................................................................... 8
Redundant Array of Independent (or Inexpensive) Disks (RAID) .......................................................... 9
Serial Advanced Technology Attachment (SATA) ................................................................................. 9
Serial Attached SCSI (SAS) ................................................................................................................... 10
Small Computer Systems Interface (SCSI) ........................................................................................... 10
Storage Area Network (SAN) ............................................................................................................... 11
Tape backup solutions ........................................................................................................................ 11
SATA ........................................................................................................................................................ 11
SCSI .......................................................................................................................................................... 12
SCSI Bus Characteristics .......................................................................................................................... 13
SCSI Topologies ....................................................................................................................................... 13
Parallel SCSI ............................................................................................................................................. 13
SCSI Performance .................................................................................................................................... 14
SCSI Reliability ......................................................................................................................................... 14
SCSI IDs .................................................................................................................................................... 15
SCSI ID Priority ........................................................................................................................................ 15
SCSI Signaling .......................................................................................................................................... 15
Single‐ended SCSI .................................................................................................................................... 16
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High Voltage Differential SCSI ................................................................................................................. 16
Low Voltage Differential SCSI .................................................................................................................. 17
Low Voltage Differential SCSI Characteristics ......................................................................................... 17
SCSI Termination ..................................................................................................................................... 17
Terminating Internal SCSI Devices .......................................................................................................... 18
Terminating a Mixed Bus ........................................................................................................................ 18
SAS .......................................................................................................................................................... 18
SAS Characteristics .................................................................................................................................. 19
SAS, SATA, and Parallel ........................................................................................................................... 19
SAS and SATA Connectors ....................................................................................................................... 20
RAID......................................................................................................................................................... 20
Serial Attached SCSI .................................................................................................................................... 21
Serial Attached SCSI ................................................................................................................................ 21
Objectives................................................................................................................................................ 21
SAS Architecture ..................................................................................................................................... 21
The PHY ................................................................................................................................................... 22
SAS Addresses and Connections ............................................................................................................. 22
Combining PHYs ...................................................................................................................................... 23
SAS Devices ............................................................................................................................................. 23
End Devices ............................................................................................................................................. 24
SAS Initiator Devices ............................................................................................................................... 24
SAS Target Devices .................................................................................................................................. 24
SAS Device Ports ..................................................................................................................................... 25
SAS Ports and Bandwidth ........................................................................................................................ 25
SAS Connections ..................................................................................................................................... 25
The Connection Process .......................................................................................................................... 26
SAS Targets .............................................................................................................................................. 26
JBOD Example ......................................................................................................................................... 26
Fault‐tolerant HBA Attachment to SAS Disks .......................................................................................... 27
Connection Rate Matching ..................................................................................................................... 27
Connection Rules .................................................................................................................................... 27
Multiport Example .................................................................................................................................. 28
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Service Delivery Subsystem .................................................................................................................... 29
SAS Addresses ......................................................................................................................................... 29
SAS Pathways .......................................................................................................................................... 30
SAS Domains ........................................................................................................................................... 30
SAS Domain Topology ............................................................................................................................. 31
SAS Protocols .......................................................................................................................................... 31
Bridging SAS and SATA Domains ............................................................................................................. 32
SAS Zoning ............................................................................................................................................... 32
Multiple SAS Domains ............................................................................................................................. 33
Targets in Multiple Domains ................................................................................................................... 33
SAS Domain Discovery ............................................................................................................................ 34
SAS Layer Diagram .................................................................................................................................. 34
Expander Devices .................................................................................................................................... 35
Edge Expander Devices ........................................................................................................................... 36
Edge Expander Device Ports ................................................................................................................... 36
Attaching Two Edge Expander Devices ................................................................................................... 37
Fanout Expanders ................................................................................................................................... 38
Maximum Fanout Expansion .................................................................................................................. 38
SAS Connections ..................................................................................................................................... 39
Connection Process ................................................................................................................................. 39
Connection Rules .................................................................................................................................... 39
iSCSI ............................................................................................................................................................. 41
iSCSI ......................................................................................................................................................... 41
Objectives................................................................................................................................................ 41
iSCSI ......................................................................................................................................................... 41
Defining the iSCSI Framework ................................................................................................................. 41
iSCSI Communication .............................................................................................................................. 42
Benefits of iSCSI ...................................................................................................................................... 42
Drawbacks to iSCSI .................................................................................................................................. 43
Multiple Pathway .................................................................................................................................... 43
Ethernet Jumbo Frame Support .............................................................................................................. 43
Initiators and Targets .............................................................................................................................. 44
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Initiator Characteristics ........................................................................................................................... 44
Target Characteristics ............................................................................................................................. 45
Communication ....................................................................................................................................... 45
iSCSI Frame Construction ........................................................................................................................ 46
iSCSI Naming Conventions ...................................................................................................................... 46
IQN Naming ............................................................................................................................................. 47
EUI Naming ............................................................................................................................................. 47
NAA Naming ............................................................................................................................................ 48
Device Aliases .......................................................................................................................................... 48
RAID ............................................................................................................................................................ 49
RAID......................................................................................................................................................... 49
Objectives................................................................................................................................................ 49
RAID......................................................................................................................................................... 49
RAID Is Not .............................................................................................................................................. 49
Types of RAID .......................................................................................................................................... 50
Levels of RAID ......................................................................................................................................... 50
RAID 0 ...................................................................................................................................................... 50
RAID 1 ...................................................................................................................................................... 51
RAID 5 ...................................................................................................................................................... 51
Calculating Parity .................................................................................................................................... 52
RAID 10 .................................................................................................................................................... 52
RAID 50 .................................................................................................................................................... 52
RAID Hardware ........................................................................................................................................ 53
Drives ...................................................................................................................................................... 53
Backplanes .............................................................................................................................................. 54
Controllers ............................................................................................................................................... 54
System Boards ......................................................................................................................................... 55
Storage Products ......................................................................................................................................... 56
Dell PowerVault™ Storage Products ....................................................................................................... 56
Objectives................................................................................................................................................ 56
Storage Products ..................................................................................................................................... 56
Enclosures ............................................................................................................................................... 57
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MD1000, MD3000, and MD3000i Enclosures ......................................................................................... 57
MD Control Panel .................................................................................................................................... 58
Operational Modes ................................................................................................................................. 58
Troubleshooting LEDs ............................................................................................................................. 59
Drives ...................................................................................................................................................... 60
Daisy Chaining Enclosures ....................................................................................................................... 60
Drive Slot Numbering .............................................................................................................................. 61
Drive LEDs ............................................................................................................................................... 62
Hard Drive States .................................................................................................................................... 63
Power and Cooling .................................................................................................................................. 64
RAID Controller Module .......................................................................................................................... 64
Dell PowerVault™ Storage and Backup Solutions ....................................................................................... 65
Objectives................................................................................................................................................ 65
PowerVault Tape Products...................................................................................................................... 65
Tape Drives.............................................................................................................................................. 66
Autoloaders ............................................................................................................................................. 66
Library ..................................................................................................................................................... 67
DLT/SDLT Tapes ....................................................................................................................................... 67
LTO Tapes ................................................................................................................................................ 68
Tape Compatibility .................................................................................................................................. 68
Handling Tapes ........................................................................................................................................ 69
Tape Handling Precautions ..................................................................................................................... 69
Tape Storage ........................................................................................................................................... 70
First Time Use ......................................................................................................................................... 70
Labeling Tapes ......................................................................................................................................... 71
When to Inspect the Media .................................................................................................................... 72
Media Inspection Procedure ................................................................................................................... 72
Ejecting a Stuck Tape .............................................................................................................................. 76
Cleaning ................................................................................................................................................... 77
Drivers ..................................................................................................................................................... 77
Firmware ................................................................................................................................................. 78
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General Information
Dell PowerVault™ Storage and Backup Solutions This course introduces Dell PowerVault™ storage and backup solutions. It overviews the basic technologies used in PowerVault products.
Although it uses specific examples from the PowerVault product lines, this course does not provide specific troubleshooting information about PowerVault products.
Objectives After completing this course, you will be able to:
• Differentiate between PowerVault and other Dell product lines
• Describe the basic technologies used in PowerVault products
• Explain the purpose of specific PowerVault products
Course Contents This course comprises the following modules:
Module Description
Introduction Introduces the terms and concepts used throughout the course
Serial Attached SCSI Presents an overview of Serial Attached SCSI (SAS) technology
Internet SCSI Introduces Internet SCSI (iSCSI) technology
RAID Recaps the basics of RAID
Storage Discusses PowerVault storage products
Backup Discusses PowerVault backup products
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8
The PowerVault NX1950 is one of the NAS solutions available from Dell.
PERCs are available as add‐in cards or backplanes.
• An implementation of Small Computer Systems Interface (SCSI) technology using IP network infrastructure
Network Attached Storage (NAS) • Commonly referred to as filers
• Only Windows‐based devices are currently available from Dell
• PowerVault NAS devices are identified with an N (PowerVault 775N, PowerVault NX1950)
• Use file‐based protocols—clients request a file or portion thereof:
o Network File System (NFS)
o Server Message Block (SMB)
PowerEdge™ RAID Controller (PERC) • Provides RAID capability to servers for their direct‐attached
storage
• Communicates with the management module in PowerVault products to co‐manage the array
The PowerVault MD3000i is Dell’s first iSCSI enclosure.
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One of the advantages SATA offers over PATA is a much smaller cable footprint.
Redundant Array of Independent (or Inexpensive) Disks (RAID) • Can provide:
o Redundancy to help prevent data loss
o Enhanced performance
• Can be fully implemented on a storage server's system board or backplane
• Does not eliminate the need for backups
Serial Advanced Technology Attachment (SATA) • Serial storage technology used in client computers and less
expensive servers
• Derives from Parallel ATA (Integrated Drive Electronics or IDE, now known as PATA)
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Serial Attached SCSI (SAS) • Replaces technology for parallel
SCSI
• Derives from SCSI and SATA technologies
• Uses 64‐bit SCSI IDs (world‐wide names)
• Is Plug compatible with SATA
Small Computer Systems Interface (SCSI) • A bus that connects a variety of devices such as hard drives, CD‐
ROMs, and tape drives
• Has evolved through a number of speeds, maximum device capabilities, and bandwidths
• Protocols have evolved for use in networks that do not use the SCSI topology (for example, SCSI over Ethernet)
Some SCSI connectors have 80 pins.
SATA has its own module in this course.
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12
The small SCSI network shown here includes a self‐terminating controller and an externally terminated drive.
The current SATA feature set includes:
• Half‐duplex
• Up to 3.0 gigabits per second throughput
• Up to 1 meter internal cable length
• One device per cable
• Single connector per drive
• Point‐to‐point connectivity
• Software transparent to parallel ATA
SCSI SCSI is a bus that connects a variety of devices such as hard drives, CD‐ROMs, and tape drives.
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A typical SCSI connector
SCSI Bus Characteristics Bus characteristics include:
• A controller card
o IDs do not have to be assigned sequentially.
o Higher IDs have higher priority on the bus.
– Highest priority is 7. – On wide SCSI, device IDs above 7 has lower priority than device ID 0.
• Unique IDs for each device, including the controller
• Termination
o Each end of the bus must be terminated.
o The controller is often self‐terminating.
SCSI Topologies • Parallel SCSI (usually referred to as SCSI)
• Serial Attached SCSI (SAS), which is discussed separately
Parallel SCSI Parallel SCSI is used in server and workstation systems for high performance and greater durability.
Current parallel SCSI technology includes the following features:
• Up to 320 megabytes per second
• Half‐duplex
• Up to 1.5 meter single‐ended cable or 12‐meter LVD cable
• Up to 16 devices per channel
• Single connector per drive
• Bus topology
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Higher RPMs reduce latency. Faster electronics and more powerful actuators reduce seek time.
SCSI Performance
SCSI drives can find data 40% faster than PATA drives
SCSI Reliability Because SCSI drives perform better than PATA drives, they do not have to work as hard to accomplish the same tasks, which make SCSI drives more reliable than PATA drives. A typical enterprise workload would generate 20% more work for a PATA drive than a SCSI drive.
• SCSI Disk Mean Time Between Failures (MTBF) is typically around 1 million+ hours.
• IDE MTBF typically is approximately 600,000 hours.
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SCSI IDs Each device must have a unique ID.
• SCSI IDs start at zero.
• The IDs do not have to be in sequential order.
• Higher priority is given to higher IDs. For example:
o ID 5 is a higher priority than ID 1.
o For this reason, most SCSI controllers default to ID 7.
• SCSI IDs are set by:
o Jumpers
o A dial on the device
• SCSI IDs are binary.
SCSI ID Priority The IDs in priority from highest to lowest are:
• Narrow controller: 7, 6, 5, 4, 3, 2, 1, 0
• Wide controller: 7, 6, 5, 4, 3, 2, 1, 0, 15, 14, 13, 12, 11, 10, 9, 8
SCSI Signaling Devices communicate by sending signals, or signaling. The way a SCSI controller communicates must be compatible with the way a SCSI device communicates.
The three types of SCSI signals are:
• Single‐ended
• High Voltage Differential
• Low Voltage Differential
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Single‐ended SCSI In Single‐ended (SE) signaling, one signal is sent over one wire. This is a very inexpensive way for SCSI devices to communicate.
Characteristics of Single‐Ended SCSI include:
• Used in CD‐ROMs and tape drives
• Unreliability at higher speeds
• AIC‐7860, AIC‐7880, and AHA‐2940UW
• Cable length up to six meters
• Speed limited to 40 megabytes per second
NOTE: Single‐Ended devices are not compatible with High Voltage Differential (HVD) devices.
High Voltage Differential SCSI Compared to SE SCSI, HVD signal quality is improved by using two wires to transmit a signal. One signal is a positive while the other is negative.
Characteristics of HVD SCSI include:
• Reliability at higher speeds
• Cable length up to 25 meters
• Speed limited to 80 megabytes per second
• AHA‐2944 and AHA‐3944
• PowerVault 120T DLT4000/7000 and PowerVault 130T
NOTE: HVD devices use a higher voltage to transmit the signals. SE and Low Voltage Differential (LVD) devices are rendered inoperable if connected to HVD SCSI controllers. If an HVD device is connected to an SE controller, nothing happens. The SE controller does not produce enough voltage to power the signals.
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Low Voltage Differential SCSI LVD devices:
• Use the same type of signaling technique as HVD devices
• Operate at a lower voltage than HVD devices
• Have the same high speed capability as HVD devices
• Are compatible with SE devices
Most devices that Dell ships on its servers are LVD – hard drives and newer tape drives.
NOTE: LVD devices are not compatible with HVD.
Low Voltage Differential SCSI Characteristics Characteristics of LVD SCSI Include:
• Reliability at higher speeds
• Signal sent over two wires
• Cable lengths:
o Up to 25 meters if only two devices are on the chain
o Up to 12 meters if three or more devices are on the chain
• Speed up to
o 160 megabytes per second
o 320 megabytes per second on newer controllers
• AIC‐7890, AIC‐7899, AHA‐2940U2W, AHA‐29160, and AHA‐39160
• PowerVault 122T, 124T, 128T, 132T, and 136T
SCSI Termination The first and last devices in an SCSI chain require termination.
• Termination allows the SCSI host adapter to see the first and last device, which in turn then allows the adapter to recognize the SCSI IDs of all the installed devices.
• Termination also helps prevent signal reflections from entering the SCSI bus.
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Terminating Internal SCSI Devices When all devices to be installed are internal, the SCSI host adapter is counted as an installed SCSI device. If you are installing an external device, you may have to disable the SCSI host adapter termination and terminate the last external device.
NOTE: Most SCSI peripheral devices ship with termination in the ON position. If the device that you are installing is in the middle of the chain, you should disable termination.
Terminating a Mixed Bus When mixing narrow and wide SCSI devices on the same bus, the wide devices must be the terminated devices. Otherwise, the host adapter will not see the wide devices installed in the system, as only half of the cable would be terminated.
• When terminating external SCSI 2 devices, active termination may be necessary.
• Ultra2 devices require active terminators for LVD devices.
• Differential drives require external termination, as they do not have onboard termination.
SAS Serial Attached SCSI (SAS) leverages the best of previous technologies including SCSI and Fibre Channel, and is the industry's replacement for U320/U640 Parallel SCSI.
This diagram illustrates the interconnectivity of SAS devices on the SAS chain.
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This drawing illustrates the architecture between the initiator and target devices in a SAS chain.
SAS Characteristics SAS features include:
• Serial SCSI technology
• Point‐to‐point connections through a switched network
• Storage domains allowing up to 16,000 end devices or SAS addresses per domain
• Support for SAS and SATA drives
• High performance with speeds up to 3 gigabits per second full duplex
• Aggregated links allowing for up to 24 gigabits per second full duplex when creating a wide link port utilizing 8 PHYs
• High availability features
• High connectivity options with up to 16,384 physical links supported in an SAS domain
• 64‐bit SCSI IDs (world‐wide names)
SAS, SATA, and Parallel In its most basic configuration, SAS is similar to SATA. The SAS host plug and receptacle are also the same as the SATA plug and receptacle.
• Serial technology has many advantages, including increased clock speeds.
• Parallel technology cannot operate as quickly without experiencing electro‐magnetic interference.
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SAS and SATA Connectors SAS and SATA hard drives are plug‐compatible and hot‐swappable.
• Plug differentiation allows SATA drives to operate in a SAS backplane, but SAS drives will not seat in a SATA backplane.
• SAS drives have dual ports for the opportunity of redundant pathways to the drive.
RAID RAID is a Redundant Array of Disks. Depending on your source, the I stands for either Independent or Inexpensive.
RAID is essentially a method that allows your disks to automatically protect the information they store by distributing it across two or more disks. When one disk fails, the information that would normally be lost can be rebuilt from the information on the remaining disks.
RAID is not a substitute for backing up data. A catastrophic failure of the array can still result in permanent information loss.
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Serial Attached SCSI
Serial Attached SCSI Serial Attached SCSI (SAS) is one of the storage technologies used in current PowerVault products. This module provides details of how SAS works.
Objectives After completing this module, you will be able to:
• Describe the SAS architecture
• Explain SAS domain topology and domain interconnections
• Identify SAS devices
SAS Architecture SAS architecture comprises:
• Devices
• PHYs
• Methods and rules for connection
• Pathways
• Addresses
• Domain topology
• Protocols
• Zoning
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The PHY The PHY (rhymes with "fly") is the basis of all SAS communication. A PHY consists of a minimum of:
• One transmit circuit
• One receive circuit
A pathway can then be established, consisting of:
• A transmit circuit at one end of a connection
• A receive circuit at the other end of a connection
This connection of transmit and receive pairs is called a Physical Link.
SAS Addresses and Connections The simplest pathway is known as a Narrow Link:
• Two attached PHYs, each with its own SAS address
The SAS Address is:
• A 64‐bit unique identifier
• Similar to a World Wide Name or MAC address
Connections are:
• Addressed to SAS ports, which own the SAS address
• Established from PHY to PHY
Each direction runs at a minimum of 3.0 gigabits per second, with both directions using the same Physical Link Rate. The link is full duplex.
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A Wide Link consists of two or more transmit and receive circuits with matching SAS addresses
Combining PHYs PHYs can be aggregated to:
• Provide a bigger pipe for data throughput
• Provide redundancy of pathways for fault tolerance
An aggregated set of PHYs with matching SAS addresses can be attached to another set of aggregated PHYs with matching SAS addresses to create a Wide Link. Failure of one PHY pathway does not disable the entire link.
SAS Devices SAS has two device classes:
• End devices include:
• SAS initiator devices
• SAS target devices
• SATA devices
• Expander devices include:
• Edge expanders
• Edge expander sets
• Fanout expanders
SAS initiator devices can connect to a total of 128 SAS target devices, SAS expander devices, or SATA devices.
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End Devices End Devices in a SAS topology can be generally thought of as destination devices.
In the SAS environment:
• HBAs and disk drives are the predominant devices.
• Tape and other storage media may also be developed and introduced as End Devices.
SAS Initiator Devices Initiator devices can support SAS or SATA, depending on the controller capabilities.
• Initiator devices have one or more initiator ports that support SSP and or STP (and SMP for management).
• SATA‐only initiators are not supported in a SAS domain.
SAS Target Devices Target devices may support SAS or SATA, depending on the controller capabilities and include one or more target ports.
• SATA‐only target ports may be included in SAS domains if the expander they are connected to supports STP.
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SAS Device Ports When a SAS HBA sends a frame out to a hard disk's SAS address, it sends the frame out through the port. SAS Ports:
• Are a logical expression of the PHY
• Exist at the software level
A SAS port can contain be:
• Narrow (a single PHY)
• Wide (multiple PHYs)
SAS Ports and Bandwidth A port can bundle PHYs together to increase bandwidth and resiliency. It can also be just one PHY, as in the case of a hard drive port.
The intermediary chip manages the port and chooses the appropriate PHY to use from those available at the port by enforcing the embedded algorithms in the chip's firmware, including load balancing algorithms such as:
• Round‐robin
• Least‐recently used (LRU)
SAS Connections A Connection is a temporary association between an initiator PHY and a target PHY.
A connection is like one lane of a multi‐lane highway. You can choose from multiple lanes to reach the same destination:
• You can choose from multiple lanes to reach the same destination.
The SAS Port is a logical expression of the PHY that exists at the software level
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This example shows a RAID being constructed using one of the two ports on the SAS disks.
The Connection Process A simplified description of the connection process follows:
• The source PHY transmits an OPEN address frame which contains a destination SAS address.
• The destination PHY replies with an OPEN_ACCEPT primitive.
• The connection is established and remains open.
• Both sides exchange CLOSE primitives to close the connection.
SAS Targets SAS disks always have two narrow ports, each with its own SAS Address.
• The SAS Address is a 64‐bit unique name, similar to a Fibre Channel World Wide Name.
• The SAS disk is addressable through the two port names.
• These ports do not aggregate into a wide port to protect the redundancy feature.
JBOD Example For JBOD solutions, the drive might be attached to a RAID‐capable HBA through only one of the ports on the SAS disk drive.
In direct attach configuration, the number of drives attached is limited by the number of ports available on the HBA.
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This graphic illustrates two HBAs accessing different ports on the same SAS disk.
Fault‐tolerant HBA Attachment to SAS Disks With two ports for access, software controls can allow two separate HBAs in a host (or hosts) to access the two narrow ports of the same SAS disk drive.
• These software controls include a form of ownership by a particular HBA until such time as it is unable to continue operation.
• The rules of operation resemble those found in a shared‐nothing cluster.
Connection Rate Matching A Connection operates at a fixed rate. SAS 1.0 operates at a Physical Link Rate of 3 gigabits per second. Future plans call for 6 gigabits per second and 12 gigabits per second connection rates.
If the Connection Rate is slower than the Physical Link Rate, Rate Matching uses ALIGN primitives to insert meaningless filler into the data stream between DWORDs containing the actual data. These ALIGN primitives are then stripped off at the receiver of the destination device, effectively halving the rate of transfer of meaningful data.
This allows a 6 gigabit per second device to communicate with a 3 gigabit per second device.
Connection Rules • Connections are addressed to SAS ports but are established from PHY to PHY.
• Wide ports may establish multiple connections at a time (a maximum of one per PHY) to different destinations.
• Wide ports may establish multiple connections to other wide ports simultaneously (wide initiator port to wide target port).
• Only HBAs and RAID controllers offer wide ports as End Devices.
• SAS disk drives only offer two narrow ports, to ensure alternate pathways to the device. This affords the opportunity to use fault tolerance.
28
Multiport Example A SAS HBA may have multiple PHYs and its connections can be distributed among both narrow and wide ports. A SAS HBA with six ports is shown with connections to two narrow device ports and one wide device port.
29
Service Delivery Subsystem The service delivery subsystem can be one of the following:
• A set of physical links between a SAS initiator port and a SAS target port
• A set of physical links and expander devices, supporting more than two SAS ports
SAS Addresses SAS addresses define the limitations of the different topologies. SAS addresses are assigned to:
• Each expander device
• SAS initiator devices
• SAS target devices
• SAS target/initiator devices
Ports use the SAS name for identification (port identifiers). If a SAS device has more than one port in the same domain, each port has a unique port identifier (SAS address).
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Single or multiple pathways are established when an initiator is attached to either an end device or an expander device.
SAS Pathways • A potential pathway is a set of physical links between a SAS initiator PHY and a SAS target PHY.
• When a SAS initiator PHY is directly attached to a SAS target PHY, there is one potential pathway.
• When a SAS initiator PHY is attached to an expander device, there are multiple pathways.
SAS Domains The remainder of this module explores SAS Domains, including:
• Domain topology
• Bridging multiple domains
• Zoning
• Discovery
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Three examples of SAS topologies
Three SAS protocols facilitate communication with various devices.
SAS Domain Topology Each SAS port and expander has a worldwide unique 64‐bit SAS address that uses the same construction as the Fibre Channel port name. However, SAS is not SAN. SAS‐connected devices comprise one or more SAS Domains.
SAS Protocols SAS uses different protocols to communicate between different devices:
• Serial SCSI Protocol (SSP) – SCSI protocol over SAS
• Serial Management Protocol (SMP) – Expander Management protocol
• SATA Tunneling Protocol (STP) – SATA protocol over SAS Domains
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An STP/SATA bridge enables communication between a SAS domain and a SATA domain
If implemented, zoning would isolate parts of the SAS infrastructure.
Bridging SAS and SATA Domains SAS can use SATA drives if either of these conditions exist:
• The initiator is directly connected to a SATA device.
• An expander has a SAS‐to‐SATA bridge.
In the second case, you are bridging from a SAS domain to a SATA domain. The same rule applies even if there is only one SATA device in the topology.
SAS Zoning • SAS 1.1 does not support zoning, but public pressure to implement zoning is growing.
• Zoning would isolate specific parts of the SAS infrastructure from each other.
33
Two SAS domain topologies are connected (bridged) by initiator devices.
Multiple SAS Domains Expanders:
• Connect devices in a domain, defining the domain
• Cannot reside in more than one domain
End devices:
• Cannot bridge domains by themselves
Initiators:
• Can have ports in multiple domains
Targets in Multiple Domains If multiple initiators meet only at a target device, multiple SAS domains still exist. One example is in a clustered Direct Attached Storage (DAS) environment.
This example shows two SAS Domains connected by a target end device.
34
SAS Domain Discovery Domain discovery can occur in one of two ways:
• SAS initiator controlled (version 1.0+)
o SMP application in the initiator configures expander routing
o Requires messaging from initiator to all ports in the domain
o Where multiple initiators and links exist, it results in much duplication of work
• SAS expander controlled (version 1.1+)
o Expanders and initiator devices exchange "neighbor" information
o Results in reduced overhead
Expanders adjust routing tables to account for invalid topologies, such as disabling ports that create loops.
SAS Layer Diagram
This graphic illustrates the multiple layers of SAS technology.
35
Expander Devices The term expander device covers a broad area of intermediary devices that handle connectivity without being an end device. Expander devices:
• Are intermediary devices that perform simple routing of SAS data frames addressed to end device SAS addresses
• Can contain multiple expander ports, up to a maximum specification of 128 ports, which do not have individual SAS addresses
• Are invisible to clients in the same way that clients do not see an Ethernet switch or router
36
Edge Expander Devices An edge expander can be attached:
• To SAS initiators and targets as end devices
• To other edge expander devices
Edge Expander Device Ports An expander can have up to 128 ports, which can be either narrow or wide links. The device set created from all the devices that can see each other is also limited to 128 port addresses.
For the edge expander to attach to other edge expanders, the ports must be properly configured.
• The subtractive port operates in a similar fashion to a default gateway in networking.
• The table port requires that the expander chip build and maintain a lookup table for devices that are indirectly attached.
• Direct ports are for directly attached end devices.
37
Attaching Two Edge Expander Devices Two expander device sets can be attached to each other through the subtractive port of one of the expanders for each set.
• An expander chip can have no more than one subtractive port.
• No more than two device sets can be connected together without using a fanout expander.
• Either an initiator or target can be attached to any direct attach port on an expander.
• An end device may also be attached at a table route port, in which case the port takes on the attributes of a direct attach port.
The SAS initiator (host) in the graphic can access any of the hard drives on the attached expanders by using either the expander’s subtractive port or its lookup table.
38
Fanout Expanders Fanout expanders act as core expanders as opposed to edge expanders.
• An expander device may not be connected to more than one fanout expander. This would resemble dual homing and is not allowed in SAS topology.
• The fanout expander maintains the lookup tables for the entire domain.
• The fanout expander can attach to as many as 128 expander device sets.
Maximum Fanout Expansion The maximum number of devices allowed in a SAS domain is 16,384.
• Up to 128 device sets may be attached to a fanout expander.
• Each device set may contain as many as 128 ports.
• 128 X 128 = 16,384
• Each table port and subtractive port is included in the total.
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SAS Connections A connection is:
• A temporary link between a SAS initiator port and a SAS target port
• Enabled for one protocol
o SSP
o STP
o SMP
Connection Process This procedure explains the connection process:
1. Initiator starts with an OPEN address frame.
2. Connection is pending until an OPEN_ACCEPT frame comes back.
3. Rate matching is then performed.
Connection Rules Use the following guidelines when making SAS connections:
• There can be no more than one connection on a physical link at a time.
• Connections using any part of an already open link are blocked until the initial connection closes.
• Connections are maintained until CLOSE or BREAK frames exchanged.
• 1.5 gigabit per second must be supported by all PHYs.
40
Expanders
• Reject a connection request if a requested rate is higher than its potential output.
• If at least one PHY supports the requested rate, the expander waits until it is available.
Initiators
• Use SMP discovery and decide the highest rate that works for them.
• You can try the fastest speed and keep falling back.
Targets
• Do not discover.
• Use whatever rate the initiator agrees with.
41
iSCSI
iSCSI This module presents an overview of iSCSI technology, terminology, and concepts.
Objectives After completing this module, you will be able to:
• Describe the iSCSI framework, its benefits and its drawbacks
• Apply general storage concepts to the iSCSI framework
• Describe iSCSI naming conventions
iSCSI • The Internet SCSI (iSCSI) protocol defines procedures to transmit blocks of information over IP
networks.
• iSCSI uses the IP infrastructure rather than the direct cabling scheme over a fabric network used by parallel SCSI.
• At the physical layer, iSCSI is media independent, supporting any media that also supports IP.
Defining the iSCSI Framework • Servers and storage devices with iSCSI interfaces can connect via an IP switch and router
infrastructure.
• iSCSI uses the TCP/IP protocol to transfer information.
• The iSCSI protocol resides above the physical and data link layers of the network model.
o Interfaces to the operating system’s standard SCSI Access Method command set
o Encapsulates SCSI3 commands within TCP packets to be delivered reliably over IP networks
42
iSCSI Communication • iSCSI storage devices
communicate with the initiator and the target at the block level.
• iSCSI storage devices create a file system in free space.
o No permissions are assigned.
o The file system is shared out to clients.
o iSCSI NAS acts as a gateway to the Storage Area Network (SAN).
Benefits of iSCSI Benefits of using iSCSI include:
• Scalability
• Commodity hardware
• Standard Cat‐5 cabling
• Open Standard Internet Protocol
• Existing infrastructure: switches, routers, NICs
• Native operating system support
• Long distance connectivity
o iSCSI over wide area networks (WANs) can provide cost‐effective, long distance connections
o Not limited to cable length
• Lower cost
o Uses existing infrastructure
o Minimal additional training needed, build on existing network knowledge
• Less complex implementation and management
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o Software is installed to create targets and initiators
o Uses open protocols and several free applications
Drawbacks to iSCSI iSCSI does have a few drawbacks, the most notable of which is the potential to adversely affect network traffic:
• iSCSI uses the same infrastructure as the rest of your network—as opposed to a SAN, which uses a dedicated network for storage traffic.
• The additional traffic could adversely affect:
o Performance
o Scalability
Multiple Pathway iSCSI is capable of multiple pathways:
• Require no specialize software
• Provide redundancy and greater throughput
• Provide greater resiliency as all devices are connected
• Can use multiple gigabit Ethernet adapters
Ethernet Jumbo Frame Support By using Ethernet jumbo frame support, iSCSI:
• Reduces overhead on servers and iSCSI targets
• Uses 9K frames
• Can use 16K frames when switches and NICs support it
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Initiators and Targets Definitions:
• An initiator is a client system that initiates a request.
• A target is a storage device that contains the information the initiator requests.
Relationships:
• Multiple initiators can access a single target.
• Targets can map storage space to individual initiators.
Initiator Characteristics Characteristics of initiators include:
• Seeing remote storage as usable or mountable drive space
• Formatting and using space with a file system as they would use local storage
• The ability to use:
o iSCSI HBA card – offloads iSCSI protocol from the processor
o iSCSI software with hardware offloading – assists in signal processing
o iSCSI software – uses system processor for all iSCSI processing
45
Target Characteristics Characteristics of iSCSI targets include:
• Are accessible over an IP network
• Provide access to:
o Internal hard drives
o Direct attach arrays
o External storage arrays
• May incorporate:
o Hardware RAID
o Software RAID
o Logical volumes
• May bridge iSCSI networks and Fibre Chanel networks
Communication Targets and initiators communicate over one or more TCP connections, which use iSCSI Protocol Data Units (iSCSI PDUs) to encapsulate:
• Control Messages
• Data digests
• SCSI commands, parameters, and data
46
iSCSI Frame Construction The iSCSI frame contains:
• Ethernet header – MAC address
• IP header – IP address
• TCP header – TCP ports
• iSCSI header – iSCSI naming and session information
• iSCSI data – SCSI commands and data
• Ethernet trailer – CRC checks
iSCSI Naming Conventions • Each iSCSI device requires a unique name.
o WWUI – world‐wide unique identifier
o iSCSI equivalent to Fibre Channel world‐wide name (WWN)
• Three naming conventions are in use:
o IQN – iSCSI Qualified Name
o EUI – Extended Unique Identifier
o NAA – Network Address Authority
• iSCSI names are associated with the iSCSI node, not the NIC.
• Hardware can be changed without renaming.
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IQN Naming IQN is the most commonly used convention.
• More human‐readable
• Reverse domain creation and a qualified domain to start
• Suffix can be a combination of:
o Site
o Department
o Manufacturer
o Serial number
o Asset number
EUI Naming EUI naming characteristics include:
• Registered globally as a unique identifier
• Unique identifier based on:
o Vendor‐specific code
o Hardware or software
• Name base and suffix combined to form a hex number
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NAA Naming NAA naming is:
• Used when converting Fibre Channel WWNs to iSCSI format
• Used when matching existing fabric infrastructure (SAS and Fibre Channel)
• A combination of the name base and suffix to form a unique 64‐ or 128‐character hex number
Device Aliases The iSCSI protocol provides a supplementary device alias name option.
• Helps quickly identify storage resources
• Assigned by manufacturers, so it may have little relevance to your network naming conventions
• Cannot be exchanged during device login
• Requires management software to be visible
• Can be up to 255 characters long
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RAID
RAID This module provides a quick review of RAID technology and terminology.
Objectives After completing this module, you will be able to:
• Identify the types of RAID
• Define the levels of RAID
RAID RAID is:
• An acronym for Redundant Array of Inexpensive (or Independent) Disks
• A technology that causes a bunch of hard drives to behave as one large drive with increased performance and data redundancy
o The ability of the system to remain functional when hardware fails is fault tolerance.
o Increased performance derives from dividing the signal between the drives that comprise the RAID.
RAID Is Not RAID is not a substitute for regular backups.
• Regular, secure backups are part of a Disaster Recovery Plan.
• RAID may be able to rebuild data after a drive failure. It cannot restore data lost because of a disaster that destroys the array.
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Types of RAID Two ways to create a RAID:
Type Description Benefits Drawbacks
Software Controlled by the operating system • No specialized hardware needed
• Windows 2000 and later support
o RAID 0 o RAID 1 o RAID 5
• Taxes the processor • Cannot support a Windows
boot partition in all levels • May require an alternate
boot media if a hard drive fails
Hardware • Requires a dedicated controller card
• Groups physical disks into virtual disks
o The RAID card sees the physical discs.
o The operating system sees the virtual disks
o Virtual disks are treated the same as the operating system would treat a physical disk
• Frees up processor power • Transparent to the
operating system • No boot floppies are
needed when drive failures occur
• The operating system remains fully functional in the event of a hard disk failure
• Rebuilding a drive can be as easy as replacing it.
• An IRQ used by the controller • Added expense of a RAID
controller
Levels of RAID This module discusses five levels of RAID currently available in PowerVault storage products: 0, 1, 5, 10, and 50.
RAID levels 6 and 60 simply add another layer of parity to RAID 5 and 50. RAID 6 and 60 are not currently available in PowerVault products and are not included in this module.
RAID 0 RAID 0 is also known as striping.
• Data is written across two or more drives with each write.
• The user sees only one drive.
• The data area equals the combined size of all the drives in the array.
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RAID 1 RAID 1 is also known as disk mirroring.
• Disks in the array are configured in identical pairs.
o If drives are different sizes, the data area is the size of the smaller drive.
• For every disk there is a duplicate disk containing an exact copy of all data.
o The controller writes data to both disks simultaneously.
o The controller can handle two simultaneous read requests, directing each request to a different disk in the mirror set.
• If a disk fails, I/O requests are directed to the disk’s counterpart, and normal access to data is not interrupted.
o After the defective disk is replaced, data from the surviving member of the mirror set is copied onto the new disk.
RAID 5 RAID 5 is also known as striping with distributed parity.
• A parity algorithm calculates the data in two drives and stores the results on a third.
• A failed drive can be hot swapped with a new one, and the RAID controller automatically rebuilds the lost data.
• RAID systems may also have a spare drive (hot spare) ready and waiting to be the replacement for a drive that fails.
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Calculating Parity A bit from drive 1 is compared (XOR) with a bit from drive 2, and the result bit is stored on drive 3.
• OR is a Boolean logic operation that is true if any of the inputs is true.
• An exclusive OR (XOR) is true if only one of the inputs is true, but not both.
RAID 10 RAID 10 is also known as striping with mirrors.
• Requires an even number of drives with a minimum of 4.
• Data is striped across the mirrored pairs.
RAID 50 RAID 50 is also known as striping with parity.
• Stripes data with parity across each RAID‐5 subset of disks.
• Each RAID‐5 subset requires three disks.
• Each subset can lose one disk without losing data.
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60‐pin SCSI Drive
80‐pin SCSI Drive
RAID Hardware Hardware required to create a RAID includes:
• Drives
• Backplanes
• Controllers
• System boards
Drives RAID implementations usually use SCSI drives, although SAS and SATA drives are becoming more common.
• SCSI drives
o 68‐pin
o 80‐pin
• Can be used in servers without a backplane
• Can be connected with a multi‐drop internal cable
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SCSI Backplane
Backplanes • Provide
o Power
o SCSI IDs
o Drive termination
• Use 80‐pin hard drives
• Occupy SCSI ID 6
Controllers • Two types
o Onboard
o Cards
SCSI connector on a system board
SCSI expansion card
55
System Boards • SATA
o Many embedded SATA controllers feature some level RAID capability.
• SCSI
o Some systems have a fully functional RAID controller and a fully functional SCSI controller embedded in the system board.
o These two components share a common SCSI connector so the customer can use either the SCSI controller channel or the RAID controller channel but not both at the same time.
o The RAID key and RAID cache memory must be installed before RAID can be used.
56
Storage Products
Dell PowerVault™ Storage Products This module introduces Dell PowerVault storage products.
Objectives After completing this module, you will be able to:
• Identify the chassis features of Dell Storage products
Storage Products Dell PowerVault storage products:
• Provide scalable storage solutions for your enterprise environment
• Include a range of enclosures
• Support technologies:
o Redundant Array of Independent Disks (RAID)
o Small Computer Systems Interface (SCSI)
o Serial‐attached SCSI (SAS)
o Internet SCSI (iSCSI)
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Hot‐swappable SAS, SATA, and SCSI drives form the heart of PowerVault storage
solutions
The MD1000, MD3000, and MD3000i enclosures each support up to 15 drives in
a 3u rack mountable enclosure.
Enclosures Enclosures are rack‐mountable units that:
• House multiple hot‐swappable disk drives
• Provide power and communication between the drives and servers
• Include controller functions (management module)
o PowerEdge™ RAID Controllers (PERC)
o SAS
o SATA
o iSCSI
MD1000, MD3000, and MD3000i Enclosures The MD1000, MD3000, and MD3000i enclosures share many features.
The management module differentiates them:
• RAID – MD1000
o A pass‐through module relies on the server’s PERC to control the array.
• Dual RAID – MD3000
o The management module communicates with the server’s PERC to jointly manage the array.
• iSCSI – MD3000i
o The management module controls the array and communicates with the server over the Ethernet infrastructure.
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The Control Panel used on the MD1000, MD3000, and MD3000i. Because the MD3000 and MD3000i support only unified mode, the Split Mode LED and Mode Select Switch
have no effect on the operation of these enclosures.
MD Control Panel The Control Panel used in the MD1000, MD3000, and MD3000i provides:
• Troubleshooting LEDs
• Operational Mode Switch
o MD1000 – switches between unified mode and split mode
o MD3000 and MD3000i – has no operational effect
Operational Modes The MD1000 supports two operating modes:
• Split mode
o Split mode disables two features:
• Daisy chaining enclosures • Management module failover
o The two management modules each control a separate bank of drives:
• The primary controls drives 7 – 14.
• The secondary controls drive 0 – 6.
• Unified mode
o A SAS host communicates with all 15 drives through one management module.
o If installed, the secondary management module is held in reserve in case the primary module fails.
o No drives go down unless both modules fail.
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Drives • The enclosure supports up to 15 drives.
• Although the enclosure may support both SAS and SATA drives, you cannot mix them within the same drive group.
• For proper ventilation, each drive slot must contain either a drive or a drive blank.
• Labeling indicates if an MD1000 supports SAS and SATA drives. The MD3000 and MD3000i support both.
Daisy Chaining Enclosures • You can daisy chain a MD1000 to:
o Up to two other MD1000s
o Either
• A MD3000
• A MD3000i
• You cannot chain multiple MD3000s or MD3000is together.
SATA drive showing the external face of the interposer board that enables it to connect
to the enclosure’s backplane.
61
Drive Slot Numbering
62
LEDs indicate the status and health of the individual drives.
Drive LEDs Drive LEDs convey vital information about the individual drives in the enclosure.
Identify drive Indicator Pattern
Identify Drive The green status LED indicator blinks four times per second.
Drive being prepared for removal
The green status LED indicator blinks two times per second.
Drive ready for insertion or removal
Both drive indicators are off.
Drive being prepared for operation
The green status LED indicator is on.
Drive predicted failure
The status LED indicator slowly blinks green, amber, and then off.
Drive failed The amber status LED indicator blinks four times per second.
Drive Rebuilding The green status LED indicator blinks slowly.
Drive Online The green status LED indicator is on.
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Hard Drive States The following table describes the hard drive states recognized by the controller.
State Status Description
Ready Online RAID controller module can access a hard drive but, but the hard drive is not configured as part of a virtual disk or disk group.
Online Online RAID controller module can access a hard drive, and the hard drive is configured as part of a virtual disk or disk group.
Failed Failed RAID controller module cannot access the hard drive because the drive has failed.
Configured disk Undefined A physical disk was either part of a virtual disk, was a hot spare, or was unconfigured. RAID controller module can no longer access the physical disk because it has detected an unrecoverable error on the physical disk.
Unconfigured disk or hot spare
Undefined RAID controller module has detected a hard drive that is not configured as part of a virtual disk. The disk has no link to the firmware.
Rebuild Hard drive rebuilding
RAID controller module is writing to a hard drive to restore full redundancy to a virtual disk.
Missing Undefined RAID controller module can no longer detect a hard drive that is part of a virtual disk, because the drive has been physically removed from its slot.
Hot spare Online (if not active)
RAID controller module has configured a hard drive as a hot spare
Not ready Slot empty
The hard drive is unsupported
Offline Offline RAID controller module has marked a hard drive so that RAID controller module will no longer perform any further operations on the drive. The hard drive can transition to an offline state only if all other physical disks in the disk group are marked offline. All physical disks in a disk group must be offline to avoid inconsistencies in the virtual disk.
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You can replace either power module without powering down the enclosure.
The RAID controller modules are housed just above the power supply.
Power and Cooling • The MD1000, MD3000, and MD3000i feature dual hot‐swap power supply/cooling fan modules.
• Both modules must be used for proper cooling (3+1 fan redundancy).
• A single module can be removed for up to five minutes before thermal shutdown occurs.
RAID Controller Module The MD3000 and MD3000i enclosures can house up to two controller modules.
• The MD3000 RAID Enclosure contains two RAID Controller modules.
• The MD3000i RAID Enclosure may contain either one (simplex) or two (duplex) RAID Controller modules.
65
Dell PowerVault™ Storage and Backup Solutions This module surveys Dell PowerVault tape backup solutions.
Objectives After completing this module, you will be able to:
• Describe a range of Dell backup solutions
• Explain how to maximize the life of tapes and drives
PowerVault Tape Products Dell offers a variety of tape backup solutions. Dell PowerVault tape backup solutions fall into two broad categories:
• Autoloaders are traditional tape backup units (TBUs) useful for performing daily backups in a small business.
• Libraries are enterprise solutions that robotically change tapes to perform continuous backups and manage terabytes of data.
The PowerVault MD128T (left) and ML6000 (right) exemplify the range of solutions Dell offers.
66
To provide scalability, PowerVault storage solutions package individual tape drives with other electronics and devices.
Tape Drives Like disk drives in PowerVault storage solutions, tape drives are only a small part of the picture in PowerVault backup solutions:
• Tape drives can be peripherals installed directly in a PowerEdge™ server.
• Standalone products may contain two or more drives.
• Enterprise libraries may bundle hundreds of drives with robotic devices that manage thousands of tapes.
Autoloaders Despite what the name implies, autoloaders require you to manually insert the tape. The term autoloader once differentiated these products from reel‐to‐reel tape drives.
With an autoloader, you insert the tape cassette into the drive like you would with a home VCR. The autoloader then positions
the cartridge and threads the tape past the heads.
67
Robotic extensions add to the mechanical complexity of library units and become a
primary point of failure.
The PowerVault 122T can support using DLT and SDLT tapes.
DLT VS1 tape cartridge
Library An autoloader can become a library with the addition of two optional mechanisms:
• The magazine holds a selection of tapes.
• The transport assembly or picker is a robotic device that loads tapes from the magazine into the drive.
DLT/SDLT Tapes Introduced in the mid‐1980s, Digital Linear Tape (DLT) has the following characteristics:
• ½‐inch format
• Up to 768 tracks
• Single reel
Since 2005, the two product lines are:
• DLT‐V (Value line, up to 160 GB capacity)
• SDLT or DLT‐S (Super DLT, up to 800 GB capacity)
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LTO Tapes Most PowerVault tape drives use some generation of Linear Tape‐Open ((LTO) technology. LTO tapes come in two form factors but have varying capacity, depending on their generation.
Form Size Reels
Accelis 8 mm Dual
Ultrium ½ inch Single
Generation Capacity Speed (MB/S)
Length (Meters)
Density (bits/mm)
Tracks
LTO‐1 (2000)
100 GB 15 609 4880 384
LTO‐2 (2003)
200 GB 40 609 7398 512
LTO‐3 (2005)
400 GB 80 680 9638 704
LTO‐4 (2007)
800 GB 120 820 896
LTO‐5 (Future)
1.6 TB 180
LTO‐6 (Future)
3.2 TB 270
Tape Compatibility Choosing the right tape can be confusing given that the tapes all look the same. It’s like trying to determine if optical media is a CD, CD‐R, CD‐RW, DVD‐R, DVD+R, or DVD+/‐RW by appearance only. Since the same product may ship with more than one type of drive, choosing the right tape can be even harder.
• Always check your system’s User’s Guide or Service Manual to find a compatible tape.
• Try to match replacement tapes to those already in use.
69
Dropping a cartridge can cause the tape to become loose. Loose tapes may not
feed through the drive correctly.
Handling Tapes The same precautions that help prolong the life of your VCR and cassette tapes help protect your backups:
• Never touch the tape or the leader.
o Dust and oils from your skin contaminate the tape, adversely affecting tape and drive performance.
o Acids in your skin can damage the recording media.
• If you drop a tape, inspect the media before inserting it into a drive:
o Was the cartridge damaged?
o Was the tape loosened in the cartridge?
Tape Handling Precautions When handling tape cartridges do not:
• Touch the media with your fingers
• Use pens or pencils to write on or inspect the media
• Drop the cartridge or use a cartridge that has been dropped
• Stack cartridges horizontally
• Disassemble cartridges
• Use adhesive labels
• Ship cartridges in a drive
• Place the cartridge near a speaker, monitor, or other magnetic field
• Power down a tape drive before removing the cartridge
70
Store your media vertically in protective cases.
Tape Storage Tape cartridges are reliable and durable when handled properly.
• Protect cartridges from:
o Direct sunlight
o Shock
o Vibration
o Heat – Keep between 64°‐79°F (18°‐26°C)
o Moisture – Keep between 40%‐60% relative humidity
o Magnetic fields
• Keep tapes in their protective cases when not in use.
• Store tapes vertically.
• Align cartridges so that the grooves interlock.
First Time Use Before using a cartridge for the first time (or even after it has been stored in an archive):
• Allow 24 hours for the cartridge to acclimatize to the conditions in your data center.
• Visually inspect the cartridge for damage.
71
Use the provided slide‐in labels and write in pen.
Place labels and barcodes only in the cartridge’s front label slot.
Labeling Tapes DLTtape IV, VS1, and SDLT tapes all ship with a sheet of non‐adhesive labels that fit into a slot on the front of the cartridge. To prevent cartridge or drive damage from improper labels:
• Use the slide‐in labels provided with the tape.
o Do not use adhesive labels or Post‐It® notes.
o Do not write on the cartridge.
• Write in pen, not pencil.
o Pencil lead can introduce contaminants to the tape path.
Improper labeling can damage the tape and the drive. For best results:
• Never put a label anywhere except in the front label slot.
• Never use adhesive labels.
• Store extra labels away from the cartridge.
o Labels can stick to the cartridge due to static or
humidity.
o Labels that find their way into the drive can block the drive mechanism.
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74
Step 3. Inspect the cartridge door.
• Make sure the door opens.
• Make sure the spring is present.
Media Inspection Procedure
Step 4. Operate the write‐protect switch.
• The switch should snap between the write‐protected and write‐enabled positions.
With the door open, the DLT leader should be visible and undamaged
If the write‐protect switch fails to snap into place, it may not fully engage or it
may disengage during use.
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Step 5. Make sure the cartridge leader:
• Is in the correct position
• Has not been damaged
• Stands about ‐inch (4mm) above the leader in DLT cartridges
• Does not bend in or out in SDLT cartridges
Note: When inspecting the leader, never use anything, such as a pen or pencil that could leave contaminants.
Step 6. Inspect the reel locks.
• Make sure the reel locks are visible.
• With a small flat blade screwdriver, operate the reel locks.
o When released, the reel locks should spring back to their original position.
Make sure the SDLT leader buckle aligns with the edge of the cartridge and that the metal pin is not bent or missing.
Do not use the cartridge if the reel locks are not visible or if they do not operate correctly
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Step 7. Inspect the cartridge hub.
• Make sure that the spring‐loaded hub on the bottom of the cartridge is centered.
• Press the hub.
o It should spring back when released.
Ejecting a Stuck Tape If a tape does not eject from a drive, try the following procedure to force ejection.
1. Try ejecting the tape using your backup software.
2. Press the Unload button on your drive.
3. Use the Forced Ejection procedure described in your drive’s User’s Guide or Service Manual.
4. Force a drive reset or disconnect the SCSI cable and repower the drive.
5. Run the unload test in the Dell Online Diagnostics.
6. Cycle drive power and hold the Eject button down while the drive powers up.
7. Try the Force Ejection procedure again.
8. Place a service call on the drive.
Note: Not all drives support all of these steps. Always check your drive’s User’s Guide or Service Manual.
Do not use the cartridge if the hub is not centered or fails to spring back into place.
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Firmware Updating to the most current firmware can help ensure your PowerVault tape backup performs reliably and to capacity.
• Firmware is available on support.dell.com for each product.
• Firmware usually appears under the Tape Backup header, along with drivers and utilities.