3PAR InForm® OS 2.2.4 CLI Administrator's Manual (320-200113 Rev A, March 2009)

15.3
Dynamic Optimization
InForm OS Version 2.2.4 3PAR InForm OS CLI Administrator’s Manual
15.3 Dynamic Optimization
Dynamic optimization enables you to non-disruptively re-layout virtual volumes. This
functionality promotes system optimization through improved utilization of all physical
resources present at a given time. In addition, dynamic optimization enables you to alter the
service levels associated with a given volume by changing volume parameters (for example,
RAID levels, set sizes, and disk filters).
For example, when an InServ Storage Server is upgraded by adding additional nodes, cages, or
disks, the initial volume and logical disk layouts may no longer be optimal for the new system
configuration. Dynamic optimization enables you to re-layout volumes with entirely new
parameters so as to take advantage of the current system configuration.
There are four general cases where dynamic optimization may be desirable:
 Volume re-layout upon hardware upgrade - Existing virtual volumes only take advantage
of resources that were present at the time of volume creation. However, when an InServ
Storage Server is upgraded by adding additional nodes, cages, or disks, these initial volume
and logical disk layouts may no longer be optimal. Volume re-layout enables volumes to
take full advantage of new system resources.
 Volume RAID level change - Since different RAID levels have varying capacity requirements
and offer differing degrees of performance, at some point it may be desirable to convert
volumes from one RAID type to another. Volume RAID level change enables you to
transform volume RAID levels non-disruptively.
 Volume availability level change - The availability of a virtual volume determines its level of
fault tolerance. For example, a volume with a cage-level availability can tolerate the failure
of a drive cage because its RAID sets use chunklets from different drive cages. A volume
with a mag-level availability can tolerate the failure of a drive magazine because its RAID
sets use chunklets from different magazines. As applications and business requirements
change, it may be desirable to non-disruptively alter the availability characteristics of
existing virtual volumes.
 Volume service level change - In addition to non-disruptively altering RAID and/or
availability levels for a given volume or volumes, it may also be useful to change volume
parameters such as the disk filtering parameters that are applied when creating a volume.
Each dynamic optimization operation is treated as a task (see Chapter 13, Task Management
for information about system tasks). Eight dynamic optimization tasks can run simultaneously.