HP XP P9000 Command View Advanced Edition Software Licenses - Manual (Page 169)

Optimizing storage
This module describes how to improve your storage.
About optimizing storage
HP StorageWorks P9000 Command View Advanced Edition Suite allows you to manage storage by
allocating volumes, expanding tiers and THP/Smart pools, and performing migration, based on
information acquired from checking summaries, alerts, performance statistics, and the operating status
of storage resources.
Using Smart pools, you can manage performance and capacity to optimize storage by creating parity
groups in the following dynamic tiers:
• Tier 1 using parity groups for best performance
• Tier 2 using parity groups for next best performance
• Tier 3 using parity groups for capacity independent of drive type or RAID level
Common storage optimization issues include:
• If the used capacity for a THP/Smart pool has reached or exceeded its threshold, or a volume
that satisfies a capacity requirement cannot be created or assigned because of insufficient unused
capacity, add THP/Smart pool volumes to increase the capacity of the THP/Smart pools. If the
capacity of a specific drive is insufficient when using an Smart pool, increase the capacity by
mixing different drive types or RAID levels in Tier 3.
• If the performance of a THP/Smart pool has decreased and data I/O is slow, add more THP/
Smart pool volumes to distribute loads within the THP/Smart pools. Another option is to perform
volume migration to distribute I/O loads on the THP/Smart pools.
• When using the Smart pool, performance problems may occur at certain times. Ensure that monit-
oring occurs during periods when I/O loads are occurring. You can:
• Start or stop the monitoring/relocation process manually in accordance with known times for
load changes.
• Cancel the monitoring process during periods of low activity.
• If Smart volume applications switch between online and batch processing, it can be helpful to
save optimized volume data placements, by processing method, as profiles. By applying the cor-
responding profile before beginning processing, the data placement that fits the characteristics of
the processing method is restored.
• When using Smart pools, you want to prioritize the data relocation of Smart volumes for which
capacity and access patterns vary widely, but I/O operations decrease without relocating effect-
ively. You can disable the relocation of Smart volumes for which the current data location presents
no problems, to reduce relocation load.
• When using Smart pools, important data is allocated to the lower hardware tier because it has
fewer I/O accesses. To prevent unwanted relocations, set a specific hardware tier for the Smart
pool by configuring tiering (Tier 1, Tier, and Tier 3).
• When using Smart pools, use the flexibility of tiering to spread the data in a host volume across
multiple layers of parity groups (high-speed, next highest speed, and low-speed) that are contained
in a pool structured for this purpose.
• When using Smart pools, understand that if different drive types and/or RAID levels are mixed in
a single tier, they will all be considered equal for data placement regardless of page access fre-
quency. As a result I/O performance will be dependent on the drive type characteristics and RAID
level on which any given page resides.
User Guide 169