unixdev.net


Switch to SpeakEasy.net DSL

The Modular Manual Browser

Home Page
Manual: (HP-UX-11.11)
Page:
Section:
Apropos / Subsearch:
optional field



 vxtask(1M)			  VxVM 3.5			  vxtask(1M)
				 1 Jun 2002



 NAME
      vxtask - list and administer VERITAS Volume Manager tasks

 SYNOPSIS
      vxtask abort taskid

      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 [-c count] [-t time] [-w
      wait_interval] [-ln ] monitor [taskid[taskid...]]

 DESCRIPTION
      The vxtask utility performs basic administrative operations on VERITAS
      Volume Manager (VxVM) tasks that are running on the system.
      Operations include listing tasks (subject to filtering), modifying the
      state of a task (aborting, pausing, resuming), and modifying the rate
      of progress of a task.

      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;



				    - 1 -	  Formatted:  August 2, 2006






 vxtask(1M)			  VxVM 3.5			  vxtask(1M)
				 1 Jun 2002



      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:

      task tag	A task's tag is a string that you can specify to make
		administration easier. It is usually set by the command that
		initiates the task. For most utilities, the -t tasktag
		option allows a tag to be specified as a sequence of up to
		16 alphanumeric characters.

      task type The task's type describes the specific operation that is
		being performed. For example, attaching a plex to a volume
		results in an atomic copy loop, which is represented by an
		ATOMIC_COPY task.

      description
		Describes the utility operation on whose behalf the I/O is
		being performed. For example, both a volume start and a plex
		attach can result in an atomic copy loop and thus an
		ATOMIC_COPY task. The description of the operation attempts
		to disambiguate between tasks that are performing the same
		basic work.

      object	Most tasks are related to a specific object, usually the
		volume within which the operation is taking place.

      parent	Some utilities require multiple operations to fulfill a
		request. For example, the vxrecover utility may need to
		start many different volumes. In these cases, the subtasks
		list their parent.

      progress information
		Each task has an indication of its starting point and ending
		point, and an indication as to what point it has progressed
		so far. Combined with the work time, this allows the amount
		of time remaining until completion to be estimated for some
		tasks.

      state	Each task has one of three states: RUNNING, PAUSED or
		ABORTING.

      time	Each task notes its starting time and the total amount of
		time spent doing work.

 KEYWORDS
      abort|pause|resume
		These three operations request that the specified task



				    - 2 -	  Formatted:  August 2, 2006






 vxtask(1M)			  VxVM 3.5			  vxtask(1M)
				 1 Jun 2002



		change its state.  pause puts a running task in the paused
		state, suspending its operation. resume continues the
		operation of a paused task.  abort stops the operation of
		the specified.	In most cases, the operations "back out" in
		a manner similar to when an I/O error occurs, reversing as
		much as possible what's been done so far.

      list	List tasks running on the system in one-line summaries.	 The
		value displayed for percentage task progress takes into
		account all intermediate steps that are required to
		accomplish a specific task.

		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:

		-a	  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.

		-G	  Distinguishes between volumes with the same name
			  in different diskgroups; see vxintro(1M).

		-h	  Prints tasks hierarchically with a task's child
			  tasks following the parent task.

		-l	  Prints tasks in long format.

		-p	  Limits the output to tasks in the paused state.

		-q	  Suppresses printing of column headings.

		-r	  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.

      monitor	The monitor operation continuously prints information about
		a task or group of tasks as the task information changes.
		The -l option specifies printing a long listing.  The
		default is to print  one-line listings.




				    - 3 -	  Formatted:  August 2, 2006






 vxtask(1M)			  VxVM 3.5			  vxtask(1M)
				 1 Jun 2002



		The monitor command accepts the following options:

		-c count  Prints count sets of task information, then exits.

		-n	  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).

      set	The set operation changes modifiable parameters of a task.
		There is only one modifiable parameter for tasks: the slow
		attribute, which represents a throttle on the task progress.
		The larger the slow value, the slower the progress of the
		task and the fewer system resources it consumes in a given
		time. (The slow attribute is the same attribute that many
		commands, such as vxplex, vxvol and vxrecover, accept.)

 OUTPUT
      There are two output formats printed by vxtask: a short, one-line
      summary format per task, and a long task listing. The short listing
      attempts to provide the most used task information for quick perusal,
      displaying the following fields from left to right:

	   1. The task ID for the task.

	   2. The task ID of the task's parent, if any. If the task has no
	      parent, this field is left blank.

	   3. 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.

	   4. The percentage of the operation that has been completed to
	      this point.

	   5. The task's progress information. For basic tasks, this is the
	      starting offset, ending offset and current offset for the



				    - 4 -	  Formatted:  August 2, 2006






 vxtask(1M)			  VxVM 3.5			  vxtask(1M)
				 1 Jun 2002



	      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.

	   6. 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.
      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:

      Operation:
		A description of the operation on whose behalf the work is
		being performed. This is essentially a description of the
		command executed along with the VERITAS Volume Manager
		objects specified as arguments.

      Progress: A description of the progress of the task. The progress is
		stated as a percentage of completion, along with the actual
		progress values for the task.

      Started:	The time that the task was started.

      Task:	General information for the task. The task's ID, followed by
		its parent's ID (if any) in parentheses, followed by the
		task's state, either RUNNING, PAUSED or ABORTING.

      Throttle	The throttle value for the task, if applicable.

      Type:	The task type, describing the work being performed.

      Work time:
		States how much time has been spent performing the work, and
		a rough estimate of the time remaining for the task to
		complete.

      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.

 EXAMPLES
      To list all tasks currently running on the system:




				    - 5 -	  Formatted:  August 2, 2006






 vxtask(1M)			  VxVM 3.5			  vxtask(1M)
				 1 Jun 2002



	   vxtask list


      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


 FILES
      /dev/vx/info		    Used to get task information from the
				    kernel.

      /dev/vx/taskmon		    Task monitoring device.

 SEE ALSO
      vxintro(1M), vxplex(1M), vxrecover(1M), vxsd(1M), vxvol(1M)






















				    - 6 -	  Formatted:  August 2, 2006