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vxtask [-ahlpqr ] [-g dg_name [-g dg_name...]] [[-G dg_name] -v volume [-v volume...\]] [-i taskid] list [taskid...\]
vxtask pause taskid
vxtask resume taskid
vxtask [-i taskid] set name=value taskid
vxtask [-c count] [-t time] [-w wait_interval] [-ln ] monitor [taskid[taskid...\]]
Veritas Volume Manager tasks represent long-term operations in progress on the system. Every task provides the time the operation started, the size and progress of the operation, and the operation's state and rate of progress (throttle). You can change the state of a task, giving coarse-grained control over an operation's progress. For those operations that support throttling, you can change the rate of progress of a task, giving more fine-grained control over the task.
The majority of tasks represent I/O being performed to objects. Operations such as read-writeback recovery for mirrored volumes, parity recalculation for RAID-5 volumes, volume relayouts, and so forth, all involve moderate to large amounts of I/O. Tasks that represent operations that perform I/O directly are referred to as basic tasks. The task progress information for basic tasks consists of the starting and ending block of the I/O to be performed and the offset to which the I/O has currently completed.
Some operations, such as vxrecover and starting RAID-5 volumes, may require multiple tasks to complete the operation. vxrecover may determine that many recoveries are required, some that must be performed serially. Starting a RAID-5 volume requires that its log (if any) be replayed and cleared, its parity be recalculated (if necessary), any stale subdisks be resynchronized (if needed), and that these tasks be performed serially. In these and similar cases, an overall task is created to keep track of the underlying basic tasks being performed, and these are known as parent tasks. The progress information for parent tasks are the total number of subtasks required to complete the overall operation; the number of subtasks completed; and the number of subtasks currently running.
Every task is given a unique task identifier. This is a numeric identifier for the task that can be specified to the vxtask utility to specifically identify a single task.
Tasks also contain the following information:
By default, all tasks running on the system are printed. If a taskid argument is supplied, the output is limited to those tasks whose taskid or task tag match taskid. The remaining options filter and limit the listed tasks as follows:
- Limits the output to tasks in the aborting state.
- -g dg_name
- Limits the listed tasks to those tasks running on objects in the diskgroup dg_name.
- Distinguishes between volumes with the same name in different diskgroups; see vxintro(1M).
- Prints tasks hierarchically with a task's child tasks following the parent task.
- Prints tasks in long format.
- Limits the output to tasks in the paused state.
- Suppresses printing of column headings.
- Limits the output to tasks in the running state.
- -v volume
- Limits the output to tasks whose object is volume.
Any task meeting any of the criteria specified are printed. That is, if -v foovol and -p are specified, then any task operating on foovol or that is paused are printed. If -h were also specified, then those tasks and all their children would be listed.
The monitor command accepts the following options:
- -c count
- Prints count sets of task information, then exits.
- Monitors not only the tasks specified on the command line, but also any tasks newly registered while the program is running.
- -t time
- Exits after time seconds.
- -w interval
- Prints the string "waiting" when interval seconds pass with no output activity.
In addition to printing task information when a task state changes, output is also generated when the task completes. When this occurs, the task state is printed as EXITED (see the OUTPUT section).
The long output format prints all available information for a task, spanning multiple lines. If more than one task is printed, the output for different tasks is separated by a single blank line. Each line in the long output format contains a title for the line, followed by a colon (:), followed by the information. The possible information printed for a task includes:
- The task ID for the task.
- The task ID of the task's parent, if any. If the task has no parent, this field is left blank.
- The task type and state, separated by a slash (/). The type field is a description of the work being performed, such as ATOMIC COPY for atomic copy I/O and RELAYOUT for an online relayout operation. The state is a single letter representing the task state: R for running, P for paused, and K for aborting. In the special case of the completion of a task that is being monitored, the state is printed as EXITING.
- The percentage of the operation that has been completed to this point.
- The task's progress information. For basic tasks, this is the starting offset, ending offset and current offset for the operation, separated by slashes (/). For parent tasks, this is the starting number of child tasks, total number of child tasks required for the operation to complete, and the number of child tasks already completed to this point, separated by slashes, followed by the number of children currently running in parentheses.
- A description of the command for which the task is performing work. This is normally a single word, such as START for a volume start operation or RELAYOUT for an online relayout, followed by object names, indicating what the arguments were for the command. See EXAMPLES below.
- 7. For tasks that are being processed remotely, the name of the cluster
- node on which the task is being processed is displayed at the end of the line within parentheses.
As a special case, when a task being monitored completes only the Task: line is printed for the task, with the task state represented by EXITED.
To trace all tasks in the diskgroup foodg that are currently paused, as well as any tasks with the tag sysstart:
vxtask -g foodg -p -i sysstart list
To list all tasks on the system that are currently paused:
vxtask -p list
To monitor all tasks with the tag myoperation:
vxtask monitor myoperation
To cause all tasks tagged with recovall to exit:
vxtask abort recovall
Last updated: 06 Mar 2008
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