HP XP P9500 Storage - Manual (Page 77)

If the relocation cycle’s duration is not long enough for the allocation moves to all complete, then
the amount of tier capacity used may not fully represent the desired target levels. Subsequent
relocations should eventually reach the target levels.
Smart Tiers Z 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 Z: 8
GB
•
Required capacity of cache memory for Smart Tiers Z: 4 GB
•
Therefore, in this example 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 Z, you have to remove Smart Tiers
Z.
Execution modes for tier relocation
Execution modes when using Remote Web Console
Smart Tiers Z performs tier relocations using one of 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 select an Auto execution cycle of 0.5, 1, 2, 4, or 8 hours, or a
specified time. You can specify the settings for the auto execution mode with Remote Web Console.
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 Z 77