# man vxtask
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Maintenance Commands                                   vxtask(1M)

NAME
     vxtask - list and administer Volume Manager tasks

SYNOPSIS
     vxtask abort taskid

     vxtask [-ahlpr ] [-g dg_name [-g dg_name...]]  [[-G dg_name]
     -v volume [-v volume...]]  [-i taskid] list [taskid...]

     vxtask [-c count] [-ln ] [-t time] [-w wait_interval]  moni-
     tor [taskid[taskid...]]

     vxtask pause taskid

     vxtask resume taskid

     vxtask [-i taskid] set name=value taskid

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

     Volume Manager tasks represent long-term operations in  pro-
     gress  on  the  system.  Every task gives information on the
     time the operation started, the size  and  progress  of  the
     operation,  and  the  operation's state and rate of progress
     (throttle). The administrator can  change  the  state  of  a
     task, giving coarse-grained control over an operation's pro-
     gress. For those operations  that  support  throttling,  the
     task's  rate  of  progress can be changed, 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 mir-
     rored volumes,  parity  recalculation  for  RAID-5  volumes,
     volume relayouts, etc. 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 opera-
     tion. 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

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Maintenance Commands                                   vxtask(1M)

     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:

     task tag  A task's tag is a string  that  the  administrator
               can  specify  to make administration easier. It is
               usually set by  the  command  that  initiates  the
               task.  For  most  utilities,  the tag is specified
               with the -t tag option.

     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  disambi-
               guate  between  tasks that are performing the same
               basic work.

     object    Most tasks are related to a specific object,  usu-
               ally the volume within which the operation is tak-
               ing place.

     parent    Some utilities require multiple operations to ful-
               fill 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  ad indication as to what
               point it has progressed so far. Combined with  the
               work  time, this allows the amount of time remain-
               ing until completion  to  be  estimated  for  some
               tasks.

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

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Maintenance Commands                                   vxtask(1M)

               or ABORTING.

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

KEYWORDS
     The vxtask utility supports the following operations:

     abort|pause|resume
               These three operations request that the  specified
               task  change  its  state. pause will put a running
               task in the paused state, causing  it  to  suspend
               operation. resume will cause a paused task to con-
               tinue operation. abort will  cause  the  specified
               task to cease operation. In most cases, the opera-
               tions will "back out" in a manner similar to as if
               an  I/O  error  occurred,  reversing to the extent
               possible what they had done so far.

     list      List tasks running on the system in one-line  sum-
               maries.  By default, all tasks running on the sys-
               tem are printed.  If a  taskid  argument  is  sup-
               plied,  the output is limited to those tasks whose
               taskid or task tag  match  taskid.  The  remaining
               options  filter and limit the listed tasks as fol-
               lows:

               -a        Limits the output to tasks in the abort-
                         ing 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.

               -r        Limits the output to tasks in  the  run-
                         ning state.

               -v volume Limits the output to tasks whose  object

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Maintenance Commands                                   vxtask(1M)

                         is volume.

               Any task meeting any of the criteria specified are
               printed.  That  is, if -v foovol and -p are speci-
               fied, 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 causes information  about  a
               task  or group of tasks to be printed continuously
               as  task  information  changes.  This  allows  the
               administrator  to  track  progress  on  an ongoing
               basis. Specifying -l causes a long listing  to  be
               printed;  by  default,  short one-line listing are
               printed.

               The monitor command accepts the following options:

               -c count  Causes  the  program  to  print  exactly
                         count  sets of task information and then
                         exit.

               -n        Causes the program to not  only  monitor
                         the tasks specified on the command line,
                         but to also monitor any newly registered
                         tasks while the program is running.

               -t time   Causes the program to  exit  after  time
                         seconds.

               -w interval
                         Causes the  string  "waiting..."  to  be
                         printed   when   interval  seconds  have
                         passed with no output activity.

               In addition to printing task  information  when  a
               task's  state  changes,  output  is also generated
               when the task completes.  When  this  occurs,  the
               task's  state is printed as EXITED (see the OUTPUT
               section).

     set       The set operation is  used  to  change  modifiable
               parameters of a task. Currently, there is only one
               modifiable parameter for tasks:  the  slow  attri-
               bute, which represents a throttle on the task pro-
               gress. 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 exactly the same attribute that many
               commands, such  as  vxplex,  vxvol  and  vxrecover
               accept on their command lines.)

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Maintenance Commands                                   vxtask(1M)

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  com-
             pleted to this point.

          5. 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.

          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 RELAY-
             OUT  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 con-
     tains a title for the line, followed by a  colon  (:),  fol-
     lowed  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

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Maintenance Commands                                   vxtask(1M)

               description of the command executed along with the
               VxVM 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  per-
               formed.

     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:

          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

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Maintenance Commands                                   vxtask(1M)

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)

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