VERITAS Volume Manager 3.5 Administrator's Guide (September 2002)

Chapter 8, Administering Volumes

Monitoring and Controlling Tasks

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Monitoring and Controlling Tasks

Note VxVM supports this feature for private disk groups, but not for shareable disk

groups in a cluster environment.

The VxVM task monitor tracks the progress of system recovery by monitoring task

creation, maintenance, and completion. The task monitor allows you to monitor task

progress and to modify characteristics of tasks, such as pausing and recovery rate (for

example, to reduce the impact on system performance).

Specifying Task Tags

Every task is given a uniquetask identifier. This is a numeric identiﬁerfor the task that can

be speciﬁed to the vxtask utility to speciﬁcally identify a single task. Several VxVM

utilities also provide a -t option to specify an alphanumeric tag of up to 16 characters in

length. This allows you to group several tasks by associating them with the same tag.

The following utilities allow you to specify a tag using the -t option:

vxassist, vxevac, vxplex, vxreattach, vxrecover, vxresize, vxsd, and vxvol

For example, to execute a vxrecover command and track all the resulting tasks as a

group with the task tag myrecovery, use the following command:

# vxrecover -t myrecovery -b disk05

Any tasks started by the utilities invoked by vxrecover also inherit its task ID and task

tag, so establishing a parent-child task relationship.

For more information about the utilities that support task tagging, see their respective

manual pages.

Managing Tasks with vxtask

Note New tasks take time to be set up, and so may not be immediately available for use

after a command is invoked. Any script that operates on tasks may need to poll for

the existence of a new task.

You can use the vxtask command to administer operations on VxVM tasks that are

running on the system. Operations include listing tasks, modifying the state of a task

(pausing, resuming, aborting) and modifying the rate of progress of a task. For detailed

information about how to use vxtask, refer to the vxtask(1M) manual page.