[apple/system_cmds.git] / iostat.tproj / iostat.8

.\"
.\" Copyright (c) 1997 Kenneth D. Merry.
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. The name of the author may not be used to endorse or promote products
.\"    derived from this software without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" $FreeBSD: src/usr.sbin/iostat/iostat.8,v 1.20 2001/08/07 13:59:48 ru Exp $
.\"
.\" Copyright (c) 1985, 1991, 1993
.\"	The Regents of the University of California.  All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"	This product includes software developed by the University of
.\"	California, Berkeley and its contributors.
.\" 4. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\"	@(#)iostat.8	8.1 (Berkeley) 6/6/93
.\"
.Dd September 27, 2001
.Dt IOSTAT 8
.Os
.Sh NAME
.Nm iostat
.Nd report
.Tn I/O
statistics
.Sh SYNOPSIS
.Nm
.Op Fl CdKIoT?\&
.Op Fl c Ar count
.Op Fl n Ar devs
.Op Fl w Ar wait
.Op Ar drives
.Sh DESCRIPTION
.Nm Iostat
displays kernel
.Tn I/O
statistics on terminal, device and cpu operations.
The first statistics that are printed are averaged over the system uptime.
To get information about the current activity, a suitable wait time should
be specified, so that the subsequent sets of printed statistics will be
averaged over that time.
.Pp
The options are as follows:
.Bl -tag -width flag
.It Fl c
Repeat the display
.Ar count
times.
If no
.Ar wait
interval is specified, the default is 1 second.
.It Fl C
Display CPU statistics.
This is on by default, unless
.Fl d
is specified.
.It Fl d
Display only device statistics.
If this flag is turned on, only device statistics will be displayed, unless
.Fl C
or
.Fl T
is also specfied to enable the display of CPU or TTY statistics.
.It Fl I
Display total statstics for a given time period, rather than average
statistics for each second during that time period.
.It Fl K
In the blocks transferred display (-o), display block count in kilobytes rather
then the device native block size.
.It Fl n
Display up to
.Ar devs
number of devices.
.Nm
will display fewer devices if there aren't
.Ar devs
devices present.
.It Fl o
Display old-style
.Nm
device statistics.
Sectors per second, transfers per second, and miliseconds per seek are
displayed.
If
.Fl I
is specified, total blocks/sectors, total transfers, and
miliseconds per seek are displayed.
.It Fl T
Display TTY statistics.
This is on by default, unless
.Fl d
is specified.
.It Fl w
Pause
.Ar wait
seconds between each display.
If no repeat
.Ar count
is specified, the default is infinity.
.It Fl ?\&
Display a usage statement and exit.
.El
.Pp
.Nm Iostat
displays its information in the following format:
.Bl -tag -width flag
.It tty
.Bl -tag -width indent -compact
.It tin
characters read from terminals
.It tout
characters written to terminals
.El
.It devices
Device operations.
The header of the field is the device name and unit number.
.Nm
will display as many devices as will fit in a standard 80 column screen, or
the maximum number of devices in the system, whichever is smaller.
If
.Fl n
is specified on the command line,
.Nm
will display the smaller of the
requested number of devices, and the maximum number of devices in the system.
To force
.Nm
to display specific drives, their names may be supplied on the command
line.
.Nm
will not display more devices than will fit in an 80 column screen, unless
the
.Fl n
argument is given on the command line to specify a maximum number of
devices to display, or the list of specified devices exceeds 80 columns.
If fewer devices are specified on the command line than will fit in an 80
column screen,
.Nm
will show only the specified devices.
.Pp
The standard
.Nm
device display shows the following statistics:
.Pp
.Bl -tag -width indent -compact
.It KB/t
kilobytes per transfer
.It tps
transfers per second
.It MB/s
megabytes per second
.El
.Pp
The standard
.Nm
device display, with the
.Fl I
flag specified, shows the following statistics:
.Pp
.Bl -tag -width indent -compact
.It KB/t
kilobytes per transfer
.It xfrs
total number of transfers
.It MB
total number of megabytes transferred
.El
.Pp
The old-style
.Nm
display (using
.Fl o )
shows the following statistics:
.Pp
.Bl -tag -width indent -compact
.It sps
sectors transferred per second
.It tps
transfers per second
.It msps
average milliseconds per transaction
.El
.Pp
The old-style
.Nm
display, with the
.Fl I
flag specified, shows the following statistics:
.Pp
.Bl -tag -width indent -compact
.It blk
total blocks/sectors transferred
.It xfr
total transfers
.It msps
average milliseconds per transaction
.El
.It cpu
.Bl -tag -width indent -compact
.It \&us
% of cpu time in user mode
.It \&sy
% of cpu time in system mode
.It \&id
% of cpu time in idle mode
.El
.El
.Sh EXAMPLES
.Dl iostat -w 1 disk0 disk2
.Pp
Display statistics for the first and third disk devices device every
second ad infinitum.
.Pp
.Dl iostat -c 2
.Pp
Display the statistics for the first four devices in the system twice, with
a one second display interval.
.Pp
.Dl iostat -Iw 3
.Pp
Display total statistics every three seconds ad infinitum.
.Pp
.Dl iostat -odICTw 2 -c 9
.Pp
Display total statistics using the old-style output format 9 times, with
a two second interval between each measurement/display.
The
.Fl d
flag generally disables the TTY and CPU displays, but since the
.Fl T
and
.Fl C
flags are given, the TTY and CPU displays will be displayed.
.Sh SEE ALSO
.Xr fstat 1 ,
.Xr netstat 1 ,
.Xr nfsstat 1 ,
.Xr ps 1 ,
.Xr pstat 8 ,
.Pp
The sections starting with ``Interpreting system activity'' in
.%T "Installing and Operating 4.3BSD" .
.Sh HISTORY
This version of
.Nm
first appeared in
.Nm FreeBSD 3.0 .
Commit	Line	Data
b51d5b5f A	1	.\"
	2	.\" Copyright (c) 1997 Kenneth D. Merry.
	3	.\" All rights reserved.
	4	.\"
	5	.\" Redistribution and use in source and binary forms, with or without
	6	.\" modification, are permitted provided that the following conditions
	7	.\" are met:
	8	.\" 1. Redistributions of source code must retain the above copyright
	9	.\" notice, this list of conditions and the following disclaimer.
	10	.\" 2. Redistributions in binary form must reproduce the above copyright
	11	.\" notice, this list of conditions and the following disclaimer in the
	12	.\" documentation and/or other materials provided with the distribution.
	13	.\" 3. The name of the author may not be used to endorse or promote products
	14	.\" derived from this software without specific prior written permission.
	15	.\"
	16	.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
	17	.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	18	.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	19	.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
	20	.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	21	.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	22	.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	23	.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	24	.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	25	.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	26	.\" SUCH DAMAGE.
	27	.\"
	28	.\" $FreeBSD: src/usr.sbin/iostat/iostat.8,v 1.20 2001/08/07 13:59:48 ru Exp $
	29	.\"
1815bff5 A	30	.\" Copyright (c) 1985, 1991, 1993
	31	.\" The Regents of the University of California. All rights reserved.
	32	.\"
	33	.\" Redistribution and use in source and binary forms, with or without
	34	.\" modification, are permitted provided that the following conditions
	35	.\" are met:
	36	.\" 1. Redistributions of source code must retain the above copyright
	37	.\" notice, this list of conditions and the following disclaimer.
	38	.\" 2. Redistributions in binary form must reproduce the above copyright
	39	.\" notice, this list of conditions and the following disclaimer in the
	40	.\" documentation and/or other materials provided with the distribution.
	41	.\" 3. All advertising materials mentioning features or use of this software
	42	.\" must display the following acknowledgement:
	43	.\" This product includes software developed by the University of
	44	.\" California, Berkeley and its contributors.
	45	.\" 4. Neither the name of the University nor the names of its contributors
	46	.\" may be used to endorse or promote products derived from this software
	47	.\" without specific prior written permission.
	48	.\"
	49	.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	50	.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	51	.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	52	.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	53	.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	54	.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	55	.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	56	.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	57	.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	58	.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	59	.\" SUCH DAMAGE.
	60	.\"
	61	.\" @(#)iostat.8 8.1 (Berkeley) 6/6/93
	62	.\"
b51d5b5f	63	.Dd September 27, 2001
1815bff5	64	.Dt IOSTAT 8
b51d5b5f	65	.Os
1815bff5 A	66	.Sh NAME
	67	.Nm iostat
	68	.Nd report
	69	.Tn I/O
	70	statistics
	71	.Sh SYNOPSIS
b51d5b5f A	72	.Nm
b51d5b5f A	73	.Op Fl CdKIoT?\&
1815bff5	74	.Op Fl c Ar count
b51d5b5f	75	.Op Fl n Ar devs
1815bff5 A	76	.Op Fl w Ar wait
	77	.Op Ar drives
	78	.Sh DESCRIPTION
	79	.Nm Iostat
	80	displays kernel
	81	.Tn I/O
b51d5b5f A	82	statistics on terminal, device and cpu operations.
	83	The first statistics that are printed are averaged over the system uptime.
	84	To get information about the current activity, a suitable wait time should
	85	be specified, so that the subsequent sets of printed statistics will be
	86	averaged over that time.
1815bff5 A	87	.Pp
	88	The options are as follows:
	89	.Bl -tag -width flag
	90	.It Fl c
	91	Repeat the display
	92	.Ar count
	93	times.
1815bff5 A	94	If no
	95	.Ar wait
	96	interval is specified, the default is 1 second.
b51d5b5f A	97	.It Fl C
	98	Display CPU statistics.
	99	This is on by default, unless
	100	.Fl d
	101	is specified.
	102	.It Fl d
	103	Display only device statistics.
	104	If this flag is turned on, only device statistics will be displayed, unless
	105	.Fl C
	106	or
	107	.Fl T
	108	is also specfied to enable the display of CPU or TTY statistics.
	109	.It Fl I
	110	Display total statstics for a given time period, rather than average
	111	statistics for each second during that time period.
	112	.It Fl K
20e66415	113	In the blocks transferred display (-o), display block count in kilobytes rather
b51d5b5f A	114	then the device native block size.
	115	.It Fl n
	116	Display up to
	117	.Ar devs
	118	number of devices.
	119	.Nm
	120	will display fewer devices if there aren't
	121	.Ar devs
	122	devices present.
	123	.It Fl o
	124	Display old-style
	125	.Nm
	126	device statistics.
	127	Sectors per second, transfers per second, and miliseconds per seek are
	128	displayed.
	129	If
	130	.Fl I
	131	is specified, total blocks/sectors, total transfers, and
	132	miliseconds per seek are displayed.
	133	.It Fl T
	134	Display TTY statistics.
	135	This is on by default, unless
	136	.Fl d
	137	is specified.
1815bff5 A	138	.It Fl w
	139	Pause
	140	.Ar wait
	141	seconds between each display.
	142	If no repeat
	143	.Ar count
	144	is specified, the default is infinity.
b51d5b5f A	145	.It Fl ?\&
b51d5b5f A	146	Display a usage statement and exit.
1815bff5 A	147	.El
	148	.Pp
	149	.Nm Iostat
	150	displays its information in the following format:
	151	.Bl -tag -width flag
	152	.It tty
	153	.Bl -tag -width indent -compact
	154	.It tin
	155	characters read from terminals
	156	.It tout
	157	characters written to terminals
	158	.El
b51d5b5f A	159	.It devices
	160	Device operations.
	161	The header of the field is the device name and unit number.
	162	.Nm
	163	will display as many devices as will fit in a standard 80 column screen, or
	164	the maximum number of devices in the system, whichever is smaller.
	165	If
	166	.Fl n
	167	is specified on the command line,
	168	.Nm
	169	will display the smaller of the
	170	requested number of devices, and the maximum number of devices in the system.
1815bff5	171	To force
b51d5b5f	172	.Nm
1815bff5 A	173	to display specific drives, their names may be supplied on the command
1815bff5 A	174	line.
b51d5b5f A	175	.Nm
	176	will not display more devices than will fit in an 80 column screen, unless
	177	the
	178	.Fl n
	179	argument is given on the command line to specify a maximum number of
	180	devices to display, or the list of specified devices exceeds 80 columns.
	181	If fewer devices are specified on the command line than will fit in an 80
	182	column screen,
	183	.Nm
	184	will show only the specified devices.
	185	.Pp
	186	The standard
	187	.Nm
	188	device display shows the following statistics:
	189	.Pp
	190	.Bl -tag -width indent -compact
	191	.It KB/t
	192	kilobytes per transfer
	193	.It tps
	194	transfers per second
	195	.It MB/s
	196	megabytes per second
	197	.El
	198	.Pp
	199	The standard
	200	.Nm
	201	device display, with the
	202	.Fl I
	203	flag specified, shows the following statistics:
	204	.Pp
	205	.Bl -tag -width indent -compact
	206	.It KB/t
	207	kilobytes per transfer
	208	.It xfrs
	209	total number of transfers
	210	.It MB
	211	total number of megabytes transferred
	212	.El
	213	.Pp
	214	The old-style
	215	.Nm
	216	display (using
	217	.Fl o )
	218	shows the following statistics:
1815bff5 A	219	.Pp
	220	.Bl -tag -width indent -compact
	221	.It sps
	222	sectors transferred per second
	223	.It tps
	224	transfers per second
	225	.It msps
b51d5b5f A	226	average milliseconds per transaction
	227	.El
	228	.Pp
	229	The old-style
	230	.Nm
	231	display, with the
	232	.Fl I
	233	flag specified, shows the following statistics:
	234	.Pp
	235	.Bl -tag -width indent -compact
	236	.It blk
	237	total blocks/sectors transferred
	238	.It xfr
	239	total transfers
	240	.It msps
	241	average milliseconds per transaction
1815bff5 A	242	.El
	243	.It cpu
	244	.Bl -tag -width indent -compact
	245	.It \&us
	246	% of cpu time in user mode
1815bff5 A	247	.It \&sy
	248	% of cpu time in system mode
	249	.It \&id
	250	% of cpu time in idle mode
	251	.El
	252	.El
b51d5b5f A	253	.Sh EXAMPLES
	254	.Dl iostat -w 1 disk0 disk2
	255	.Pp
	256	Display statistics for the first and third disk devices device every
	257	second ad infinitum.
	258	.Pp
	259	.Dl iostat -c 2
	260	.Pp
	261	Display the statistics for the first four devices in the system twice, with
	262	a one second display interval.
	263	.Pp
	264	.Dl iostat -Iw 3
	265	.Pp
	266	Display total statistics every three seconds ad infinitum.
	267	.Pp
	268	.Dl iostat -odICTw 2 -c 9
	269	.Pp
	270	Display total statistics using the old-style output format 9 times, with
	271	a two second interval between each measurement/display.
	272	The
	273	.Fl d
	274	flag generally disables the TTY and CPU displays, but since the
	275	.Fl T
	276	and
	277	.Fl C
	278	flags are given, the TTY and CPU displays will be displayed.
1815bff5 A	279	.Sh SEE ALSO
	280	.Xr fstat 1 ,
	281	.Xr netstat 1 ,
	282	.Xr nfsstat 1 ,
b51d5b5f A	283	.Xr ps 1 ,
b51d5b5f A	284	.Xr pstat 8 ,
1815bff5 A	285	.Pp
	286	The sections starting with ``Interpreting system activity'' in
	287	.%T "Installing and Operating 4.3BSD" .
b51d5b5f A	288	.Sh HISTORY
	289	This version of
	290	.Nm
	291	first appeared in
	292	.Nm FreeBSD 3.0 .