HP 3PAR System Reporter Software - Manual (Page 278)

9.6 Configuring Adaptive Optimization
3PAR System Reporter User’s Guide System Reporter 2.8
■ Mode -- Optimization mode (Cost/Performance/Balanced. See 9.3.4 Adaptive Optimization
Mode on page 9.10).
■ Active -- Indicates whether or not optimization is currently implemented (true/false).
■ Change -- Clicking on this link brings up a screen used to change the configuration.
9.3.1 Tier Definition (CPG Name and GiB)
Each tier is defined by the CPG and the maximum space that the tier should use. The CPG
definition includes all the parameters necessary to define a storage tier’s quality of service: the
disk type, disk speed, RAID type, etc. You can specify either two or three tiers. When you
specify two tiers you can choose which tier to leave out by setting its CPG to “-”.
The maximum space in GiB for the tier allows you to limit how much space in a tier is available
for a given configuration. If you do not want to place a limit on the amount of space for a tier,
you can enter a large value that is unlikely to be exceeded.
Adaptive Optimization looks at several limits on the CPG:
■ The CPG allocation (hard) limit
■ The CPG warning limit
■ The AO space limit for the tier
Adaptive Optimization takes the minimum of these limits and treats that as a space limit for
the CPG and attempts to keep the total LD used space in the CPG below this limit (by a margin
of about two times the grow size of the CPG).
NOTE: When you specify two tiers, for the purposes of analysis and data
movement only the order of the tiers matters, not the actual tier number. For
example specifying tiers 0 and 1 is equivalent to specifying 0 and 2 or 1 and 2. The
lower numbered tier is considered the faster tier and the higher numbered tier is
considered the slower tier.
However, you should consider whether you may want to add a tier in the future,
and if so what tier number that is likely to be, and leave out that tier number for
the two tier configuration. For example, if you have SSD PDs and NL PDs, you may
want to use SSD PDs for the tier 0 CPG, NL PDs for the tier 2 CPG, and leave tier 1
empty for the possibility of a CPG using FC PDs.