HP XP P9500 Storage - Manual (Page 79)

Smart Tiers cache specifications and requirements
The following cache capacity is required when the total capacity is 128 TB:
•
Recommended capacity of cache memory for data: 28 GB
•
Required capacity of cache memory for control information for using Thin Provisioning: 8 GB
•
Required capacity of cache memory for Smart Tiers: 4 GB
•
Therefore, 40 GB of capacity of cache memory is required.
Note that cache memory is installed in pairs. Therefore, actual capacity is twice the cache memory
capacity. For example, if required controlling information is 8 GB, then actual installed capacity
is 16 GB.
To decrease the capacity of the cache memory for Smart Tiers, you have to remove Smart Tiers.
Execution modes for tier relocation
Execution modes when using Remote Web Console and RAID Manager
Smart Tiers performs tier relocations using two execution modes: Auto and Manual. You can switch
between modes by using Remote Web Console.
Auto execution mode
In Auto execution mode, the system automatically and periodically collects monitoring data and
performs tier relocation. You can specify an Auto execution cycle of 30 minutes, or from 1, 2, 4,
8, or 24 hours. Using a 24-hour cycle, you can also specify a monitor window that is a portion
of the day.
The following illustrates tier relocation processing in a 2-hour Auto execution mode:
Manual execution mode
In Manual execution mode, you can manually collect monitoring data and relocate a tier. You can
issue commands to manually:
1. Start monitoring.
2. Stop monitoring.
3. Perform tier relocation.
The following illustrates tier relocation processing in Manual execution mode:
Smart Tiers 79