# man vxtask Reformatting page. Wait... done 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 VxVM 3.0 Last change: 11 Dec 1998 1 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 VxVM 3.0 Last change: 11 Dec 1998 2 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 VxVM 3.0 Last change: 11 Dec 1998 3 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.) VxVM 3.0 Last change: 11 Dec 1998 4 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 VxVM 3.0 Last change: 11 Dec 1998 5 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 VxVM 3.0 Last change: 11 Dec 1998 6 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) VxVM 3.0 Last change: 11 Dec 1998 7 #