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IOZTAT(8)		FreeBSD	System Manager's Manual		     IOZTAT(8)

     ioztat -- display logical I/O statistics for ZFS datasets

     ioztat -V | --version
     ioztat -h | --help
     ioztat [-DeHINnoSxyz] [-c count] [-i interval] [-T	u|d]
	    [-s	name|operations|reads|writes|throughput|nread|nwritten]
	    [dataset ...] [interval [count]]

     The ioztat	utility	displays logical I/O statistics	for individual ZFS
     datasets.	The first report is averaged over the system uptime unless
     suppressed	with -y.  If an	interval is specified, this is followed	by re-
     ports averaged over the reporting interval.  If -y	or a count is speci-
     fied, interval defaults to	one second.

     Underlying	device I/O depends on pool and dataset configuration.  See
     zpool-iostat(8) and iostat(8) for reporting on these values.

     To	filter output you may pass in a	list of	datasets.  If no datasets are
     specified,	statistics for every mounted dataset in	the system are shown.
     If	the -n option is given,	child datasets are not included	for any	speci-
     fied dataset unless they are also directly	specified.

     The options are as	follows:

     -D	   Display formatted byte sizes	using decimal powers of	1000 instead
	   of powers of	1024.

     -c	   Display count reports and exit.  This can also be specified after
	   an interval at the end of the argument list.	 If interval is	speci-
	   fied	but not	count then it defaults to infinity, otherwise it de-
	   faults to one.

     -e	   Display exact values, without truncating dataset names (unless -p
	   is given) or	formatting numeric output.

     -H	   Scripted mode, skip headers and tab-separate	fields instead of us-
	   ing arbitrary whitespace.

     -h, --help
	   Display help	text and exit.

     -I	   Display total statistics since the last report instead of averages

     -i	   Pause interval seconds between reports.  This can also be specified
	   at the end of the argument list, prior to an	optional count.	 If no
	   interval is specified the default is	1 second.

	   The ioztat command will accept non-integer intervals, but it	should
	   be noted the	reporting interval is not exact.

     -N	   Display headers only	once, instead of periodically repeating	them.

     -n	   Omit	children of any	specified datasets that	haven't	themselves
	   been	explicitly specified.

     -o	   Overwrite mode.  Before each	report,	clear the screen and print
	   only	as many	lines as will fit.

     -P	   Display dataset names on a single line.

     -p	   Display dataset names as an indented	tree spread across multiple
	   lines.  These options override defaults that	may be applied by dif-
	   ferent sorting and display modes.

     -S	   Sum child dataset statistics	into their parents.  This can be use-
	   ful when combined with -n to	omit display of	child datasets while
	   still seeing	associated I/O.

     -s	   Sort	each report by the specified order.  Defaults to name.

     -T	u|d
	   Before each report, display a timestamp.  Specify u for a numeric
	   Unix	timestamp in seconds since the epoch, or d for a formatted

     -V, --version
	   Display the current version of ioztat and exit.

     -x	   Specified once, display an opsize group containing throughput di-
	   vided by operations,	giving the average byte	size of	each I/O.
	   Specified twice, also display an unlinks section giving a count of
	   the number of files and directories queued for deletion, and	the
	   number which	have been deleted.

     -y	   Omit	statistics since boot.	This suppresses	output for the first
	   interval seconds.

     -z	   Omit	datasets which have no activity.

	   ioztat rpool/USERDATA 1

     Display per-second	statistics for any mounted datasets within rpool/USER-

	   ioztat -zoTd	-s operations 5

     Display statistics	for all	mounted	datasets with activity across five
     second intervals, ordered by total	read and write operations, limited by
     available display and overwriting prior reports in	a manner similar to

	   ioztat -SIn rpool

     Display sum total of I/O for all datasets within rpool since boot.

	   ioztat -Hey

     Display a single one-second report	for all	mounted	datasets, using	a ma-
     chine-readable format omitting headers, using tab-delimited fields, and
     providing exact values.

     iostat(8),	zfs(8),	zpool-iostat(8)

     Please report any issues at

FreeBSD	13.0		       January 29, 2022			  FreeBSD 13.0


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