Sun Microsystems StorageTek StreamLine SL8500, System Assurance Manual

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Content Management
136 SL8500: Systems Assurance Guide • July 2011 • E24254-01
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Dedicating Rails
• Ideally, try to confine each workload to a single LSM to reduce
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pass-thru activity—this improves performance.
• Allocate rails to each major application.
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For example : HSM and VSM both need tape drives and media.
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Plan separate rails for these types of applications.
• Using rails that are adjacent to each other.
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This provides a shorter distance for the pass-thru operation.
• Pass-thru’s are either:
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Vertical: using the elevator in the same library, or
- Horizontal: using pass-thru ports (PTPs) to a different library
Media types
Scratch cartridge pools
Adequate free cells
• Make sure the rails have compatible cartridges for the tape drives
• Make sure the rails have enough scratch cartridges
• Make sure there are adequate free cells so cartridges can float upon
dismount
• Avoid using the top rail to support an application that requires a
significant number of ejects and enters. To enter and eject cartridges
from LSM 0 requires elevator pass-thru activity.
• Consider using the top rail as an archival LSM—one that uses less
active tapes; or
• Use the top rail as an LSM with very active tapes that requires fast
access–using T9840C tape drives, with few enters and ejects.
• Whenever possible, enter cartridges through the cartridge access
ports (CAPs).
• When planning the workloads, place applications that require
significant enters and ejects on rails adjacent to CAP magazines.
The SL8500 is not just another library. The SL8500 architecture is four separate library storage
modules that work together in parallel (LSM / rail). This architecture offers extremely flexible and
scalable configurations that can simplify automated tape applications.
Instead of distributing cartridges and tape drives evenly across all the rails...
Look at it from a business perspective and logically plan each individual LSM / rail to meet the
customer’s specific needs and business requirements. Allocate separate tape application
workloads to specific library storage modules.
Recommendations include:
❏
Separate rails
If this is not possible because the workload is too large, consider
breaking the workload into smaller segments that do fit.
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Combine workloads If you are not able to easily separate the workload, consider:
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Populate the rails When populating the rails:
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Use of the top rail
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Enters and Ejects