cache_mgt Command

Purpose

Syntax

cache_mgt object action [-I [level]] [-T [timeout]]

Cache device management command

cache_mgt device list [-l]

Cache pool management commands

cache_mgt pool list [-l]
cache_mgt pool create -d devName[,devName,...][-p poolName] [-f]
cache_mgt pool remove [-p poolName] [-f]
cache_mgt pool extend [-p poolName] -d devName[,devName,...] [-f]

Cache partition management commands

cache_mgt partition list [-l]
cache_mgt partition create [-p poolName] -s partitionSize [-P partitionName]
cache_mgt partition remove [-P partitionName] [-f]
cache_mgt partition extend [-P partitionName] -s partitionSize
cache_mgt partition assign [-P partitionName] -t targetDevName
cache_mgt partition unassign {-t targetDevName | [-P partitionName]} [-f]

Commands to manage caching on target devices

cache_mgt cache list
cache_mgt cache start {-t targetDevName -P partitionName | -t {targetDevName | all} | -f}
cache_mgt cache stop {-t {targetDevName | all} | -p {poolName | all}}

Statistics monitoring commands

cache_mgt monitor start
cache_mgt monitor stop
cache_mgt monitor get {-h -s | -h | -s}

Commands to manage cache engine

cache_mgt engine list [-l]
cache_mgt engine register -n cePath
cache_mgt engine unregister [-n cePath]

Description

The cache_mgt command is used to manage caching on SSD devices. This command provides the following functions:

• List available SSD devices that can be used to create or extend cache pools on the system.
• Create, remove, extend, and list the cache pools on the system. A cache pool is a group of SSD devices. Cache partitions are created from the cache pool.
• Create, remove, extend, assign, unassign, and list the cache partitions on the system. A cache partition is a part of the cache pool. A cache partition must be assigned to a target device that needs to be cached.
• Start and stop caching of a target device. It also lists the cache partitions along with the assigned target devices and its caching status. A cache engine must be registered before the caching is initiated.
• Monitor cache statistics.
• Register and unregister the cache engine. It also lists the registered cache engine information.

Caching modes

Caching can be performed in one of the following modes:

Physical mode

Cache devices (or SSD devices) are directly assigned to a logical partition (LPAR). The cache_mgt commands can be used to manage cache pool, cache partitions, and caching of a target device.

Virtual mode

Cache devices (or SSD devices) are assigned to the Virtual I/O Server. The cache pool and cache partitions are managed on the Virtual I/O Server. Cache partitions on Virtual I/O Server can be virtualized (virtual cache devices) to client LPAR through virtual SCSI. Cache partition assignment and caching must be managed on the LPAR.

Cache engine information

The cache engine module caches the target devices on to the cache partitions. A cache engine is included by default and it is automatically registered on the client LPARs.

Only a single cache pool is supported in the physical mode and caching can be started only on a single cache partition.

Flags

Cache device management commands

Cache pool management commands

Cache partition management commands

Commands to manage caching on target devices

Statistics monitoring commands

Commands to manage the cache engine