HP XP P9500 Storage - Manual (Page 81)

Categories of data may be based on levels of protection needed, performance requirements,
frequency of use, and other considerations. Using different types of storage tiers helps reduce
storage costs and improve performance.
Because assigning data to particular media may be an ongoing and complex activity, Smart Tiers
software automatically manages the process based on user-defined policies.
As an example of the additional implementation of tiered storage, tier 1 data (such as mission-critical
or recently accessed data) might be stored on expensive and high-quality media such as
double-parity RAIDs (redundant arrays of independent disks). Tier 2 data (such as financial or
seldom-used data) might be stored on less expensive storage media.
Tier monitoring and data relocation
Smart Tiers uses storage tiers to manage data storage. It classifies the specified data drives grouped
in the pool into tiers (storage hierarchy). Up to three tiers can be defined in a pool depending on
the processing capacity of the data drives. Tiering allocates more frequently accessed data to the
upper tier and less frequently accessed data, stored for a long period of time, to the lower tier.
Multi-tier pool Pool
With Smart Tiers, you can enable the multi-tier pool Pool option for an existing pool. The default
is to allow tier relocation for each THP V-VOL. Only the THP V-VOLs for which tier relocation is
enabled are subject to calculation of the tier range value, and tier relocation will be performed on
them. If tier relocation is disabled for all V-VOLs in a pool, tier relocation is not performed.
Figure 4 Relationship between multi-tier pool Pool and tier relocation
Tier monitoring and relocation cycles
Performance monitoring and tier relocation can be set to execute in one of two execution modes:
Auto and Manual. You can set up execution modes, or switch between modes by using either
Remote Web Console or RAID Manager.
In Auto execution mode, monitoring and relocation are continuous and automatically scheduled.
In Manual execution mode, the following operations are initiated manually.
•
Start monitoring
•
Stop monitoring and recalculate tier range values
•
Start relocation
•
Stop of relocation
In both execution modes, relocation of data is automatically determined based on monitoring
results. The settings for these execution modes can be changed nondisruptively while the pool is
in use.
•
Auto execution mode
Auto execution mode performs monitoring and tier relocation based on information collected
by monitoring at a specified constant frequency: from 0.5, 1, 2, 4, or 8, hours. All Auto
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