3PAR InForm® OS 2.3.1 CLI Administrator's Manual (320-200180 Rev B, February 2010)

16.11

Tuning Physical Disks

InForm OS Version 2.3.1 3PAR InForm CLI Administrator’s Manual

 To consolidate CPG space, issue the compactcpg <CPG_name> or compactcpg

command, where:

◆ <CPG_name> is the name of the CPG you wish to compact.

◆ <pattern> displays all CPGs that match the pattern.

Refer to the InForm OS Command Line Interface Reference and CLI Help for detailed

information about this command.

16.10 Tuning Physical Disks

3PAR System Tuner is an optional feature that improves performance by identifying over-used

physical disks, and performing load balancing on those disks without interrupting access. Use

the

tunepd command to perform tuning tasks on physical disks. You must purchase the 3PAR

System Tuner license to use the

tunepd command.

If the performance of one or more physical disks degrades, the throughput of the logical disks

is reduced and the entire system performance may decline. There are two general reasons why

a physical disk may have degraded performance:

■ The physical disk has reached its maximum throughput due to an unbalanced load. A disk

in this state typically has unusually high average service times when compared to other

disks.

■ The physical disk is a bad disk. A bad disk typically has unusually high maximum service

times when compared to other disks.

The

tunepd command allows you to:

■ Perform physical disk performance tuning on an entire InServ Storage Server or on a

specified subset of disks.

■ Set performance thresholds for physical disk tuning.

■ Identify and relocate under-performing chunklets.

In the following example, physical disks with average service times exceeding 50 milliseconds

are identified and their chunklets are automatically relocated to re-balance the load on the

physical disks.

 To tune physical disks, issue the tunepd -vvlayout -chstat -movech auto avgsvct

command, where: