Execution Modes For Tier Relocation; Execution Modes When Using Remote Web Console - HP XP7 User Manual

You can set the External LDEV Tier Rank when creating the pool, changing the pool capacity, or
setting the Edit External LDEV Tier Rank window. The following table explains the performance
priority (from the top) of data drives.
Priority
1
2
3
4
5
6
7
*Displays as External Storage in the Drive Type/RPM.
Reserved pages for relocation operation:A small percentage of pages, normally 2, are reserved
per tier to allow relocation to operate. These are the buffer spaces for tier relocation.
Tier relocation workflow:Tier relocation is performed taking advantage of the buffer space allocated
for tier relocation, as mentioned above. Tier relocation is also performed to secure the space
reserved in each tier for new page assignment. The area is called the buffer space for new page
assignments. When tier relocation is performed, Smart Tiers Z reserves buffer spaces for relocation
and new page assignment.
During relocation, a tier may temporarily be assigned over 98% of capacity as well, or well under
the allowance for the buffer areas.

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.
The following illustrates tier relocation processing in a 2-hour Auto execution mode:
82 Configuring thin provisioning
Data drive type
SSD
SAS 15K rpm
SAS 10K rpm
SAS 7.2K rpm
External volume* (High)
External volume* (Middle)
External volume* (Low)