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volstat(8)							   volstat(8)



NAME

  volstat - Logical Storage Manager statistics management utility

SYNOPSIS

  /usr/sbin/volstat [-g	diskgroup] [-i interval] [-c count] [-f	format]	[-r]
  [-psvd] [object...]

OPTIONS

  The following	options	are recognized:

  -g diskgroup
      Selects records from the specified disk group. The diskgroup option
      argument can be either a disk group name or disk group ID. If no disk
      group is specified then the rootdg disk group is assumed unless speci-
      fied objects cannot be found in rootdg but can be	found uniquely in
      another disk group.

  -i interval
      Prints the change	in volume statistics that occurs after every interval
      seconds. The first interval is assumed to	encompass the entire previous
      history of objects. Subsequent displays will show	statistics with	a
      zero value if there has been no change since the previous	interval.

  -c count
      Stops after printing interval statistics count times.

  -f format
      Specifies	the output format for the collected statistics.	The default
      is -f s. The following formats are available:

      s	  Displays statistics on read and write	operations. The	output is
	  formatted into six fields: the number	of read	operations, the
	  number of write operations, the number of blocks read, the number
	  of blocks written, the average time spent on read operations in the
	  interval, and	the average time spent on write	operations in the
	  interval.  These statistics are displayed as the default output
	  format.

      a	  Displays statistics on atomic	copies performed (has meaning only
	  for mirrored volumes)	using the following fields: number of opera-
	  tions, number	of blocks, and the average time	spent per operation.

      v	  Displays statistics on verified reads	and writes (has	meaning	only
	  for mirrored volumes)	using the following fields: number of veri-
	  fied read operations,	number of verified write operations, number
	  of blocks read, number of blocks written, average time spent on
	  verified read	operations in the interval, and	average	time spent on
	  verified write operations in the interval.

      c	  Displays the number of corrected (fixed) read	and write operations
	  (has meaning only for	mirrored or RAID5 volumes).






					 Note

	     Currently,	only read operations are corrected, so the number of
	     fixed writes will always be zero.

      f	  Displays the number of failed	read and write operations.

      b	  Displays the statistics on read-writeback mirror consistency
	  recovery operations (has meaning only	for mirrored volumes) using
	  the following	fields:	number of read-writeback operations, number
	  of blocks involved in	read-writeback operations, and average time
	  for completing a read-writeback operation. While in recovery mode,
	  most read operations to a mirrored volume invoke read-writeback
	  consistency recovery.

      F	  Displays statistics for full-stripe writes on	a RAID5	volume.	The
	  number of operations represents the number of	write operations
	  within a stripe that were conducted as a full-stripe write optimi-
	  zation. Full-stripe writes represent considerably less overhead
	  than read-modify-writes in terms of overall I/O time,	latency	and
	  CPU overhead.	 The total number of blocks represents the total size
	  of the written data and the average time is the time taken for a
	  full-stripe write operation. Since the I/O may be larger than	a
	  single stripe, more than one stripe operation	may be seen for	a
	  single logical I/O request.

      M	  Displays read-modify-write statistics. Each operation	represents a
	  read-modify write operation performed	within a stripe. I/O crossing
	  a stripe boundary is represented by more than	a single read-modify
	  write	operation. The number of blocks	counted	represents only	the
	  size of the requested	write. The read	portion	of the I/O can be
	  derived.

      W	  Displays reconstruct write statistics. Each operation	counted	is
	  for a	reconstruct write operation performed as an optimization of a
	  write	operation within a stripe. The number of blocks	counted
	  represents the count of data blocks written not including parity or
	  read operations.

      R	  Displays reconstruct read operations.	Each operation is a separate
	  reconstruct read operation. A	single stripe read or write operation
	  can lead to numerous reconstruct read	operations since each recon-
	  struction takes place	at the subdisk level. A	detached column	can
	  consist of several subdisks, each leading to a reconstruct read
	  operation.

      0	  Displays statistics for the VOL_R5_ZERO operation. Each operation
	  represents one call to the VOL_R5_ZERO ioctl.	The number of blocks
	  is based on the number of zero'd blocks written to the array.	The
	  average time is the time taken to complete the entire	ioctl opera-
	  tion.

      S	  Displays statistics for the VOL_R5_RESYNC operation. Each operation
	  count	represents one call to the VOL_R5_RESYNC ioctl.	The number of
	  blocks represents the	resulting number of blocks that	were written
	  to the parity	regions	as part	of the resynchronization of parity.
	  The read operations are not counted towards the total.

      C	  Displays statistics for the VOL_R5_RECOVER operation.	Each
	  operation count represents one call to the VOL_R5_RECOVER ioctl.
	  The number of	blocks represents the resulting	number of blocks that
	  were written to the missing column region as part of the data
	  recovery. The	read operations	are not	counted	towards	the total.

      V	  Displays statistics for the VOL_R5_VERIFY operation. Each operation
	  count	represents one call to the VOL_R5_VERIFY ioctl.	The number of
	  blocks represents the	resulting number of blocks that	were read as
	  part of the RAID5 stripes consistency	verification.

  -r  Resets statistics	instead	of printing them. This option follows the
      same selection rules as printing for any type selection arguments	or
      for any named objects. If	an interval was	specified on the command
      line, the	first set of statistics	will not be printed since they will
      have been	reset to zero. Subsequent activity will	cause printing of
      statistics as normal.

  -v  Displays statistics for volumes on the objects specified on the command
      line. If an object is a plex or a	subdisk, displays information about
      the volume with which the	object is associated.  If an object is a
      disk, displays information for any volumes that occupy any part of the
      disk.

  -p  Displays statistics for plexes on	the object specified on	the command
      line. For	subdisk	objects, displays information about a plex with	which
      it is associated.

  -s  Displays statistics for subdisks on the objects specified	on the com-
      mand line.

  -d  Displays statistics for disks on which the object	specified on the com-
      mand line	is fully or partially located.

DESCRIPTION

  The volstat utility prints and resets	statistics information on one or more
  volumes, plexes, subdisks, or	disks.

  The volstat utility reads statistics from the	/dev/volinfo device to report
  performance statistics for volume, plex, subdisk, and	disk media objects.
  The statistics are since the last reboot, the	last time they were reset, or
  for the interval specified.

  The object parameter can be the name of a volume, plex, subdisk, or disk.
  If no	object operands	are given, statistics from all volumes in the speci-
  fied disk group are reported.	 If no disk group is specified,	the rootdg
  disk group is	implied.

				     Note

       In TruCluster environments, the volstat command only reports statistic
       information for that node. It does not provide aggregate	statistic
       information for the whole TruCluster environment.

OUTPUT FORMAT

  Summary statistics for each object are printed in one-line output records,
  preceded by two header lines.	The output line	consists of blank-separated
  fields for the object	type, object name (standard), and the fields
  requested by the -f switch in	the order they are specified on	the command
  line.

  If the -i interval option was	specified, statistics are prefaced with	a
  time-stamp showing the current local time on the system.


  For example, here is a sample	of the output for a typical volstat session
  using	the default format:

       # volstat -vpsd -g data_g01 -i 10 -c 3

				OPERATIONS	     BLOCKS	   AVG TIME(ms)
       TYP NAME		      READ     WRITE	  READ	   WRITE   READ	 WRITE

       Aug 22 12:25:23 1997
       dm  dsk135	      119      210	  2944	   3392	   18.9	   2.8
       dm  dsk125	      118      212	  2928	   3424	   23.3	  22.0
       vol vol01	      237      212	  5872	   3424	   21.1	  22.0
       pl  pl-01	      118      212	  2928	   3424	   23.3	  22.0
       sd  dsk125-01	      118      212	  2928	   3424	   23.3	  22.0
       pl  pl-02	      119      210	  2944	   3392	   18.9	   2.8
       sd  dsk135-01	      119      210	  2944	   3392	   18.9	   2.8

EXIT CODES

  The volstat utility exits with a nonzero status if the attempted operation
  fails. A nonzero exit	code is	not a complete indicator of the	problems
  encountered, but rather denotes the first condition that prevented further
  execution of the utility. See	volintro(8) for	a list of standard exit
  codes.

EXAMPLES

   1.  To display statistics for LSM volumes in	the rootdg disk	group, enter:
	    # volstat -v

   2.  To display statistics for LSM volumes in	a disk group called dg1,
       enter:
	    # volstat -g dg1 -v

   3.  To display statistics for the plexes and	subdisks of a volume named
       blop, enter:
	    # volstat -ps blop

   4.  To reset	all statistics for a disk group	named foodg, enter:
	    # volstat -g foodg -r

   5.  To display 5 sets of disk statistics at 10 second intervals, enter:
	    # volstat -i 10 -c 5 -d



SEE ALSO

  Commands: volintro(8), voltrace(8)