[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 iostat
.Op Fl CUdKIoT?\&
.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 ?\&
Display a usage statement and exit.
.\" ==========
.It Fl C
Display CPU statistics.
This is on by default, unless
.Fl d
is specified.
.\" ==========
.It Fl c
Repeat the display
.Ar count
times.
If no
.Ar wait
interval is specified, the default is 1 second.
.\" ==========
.It Fl d
Display only device statistics.
If this flag is turned on, only device statistics will be displayed, unless
.Fl C
or
.Fl U
or
.Fl T
is also specfied to enable the display of CPU, load average 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 iostat
will display fewer devices if there aren't
.Ar devs
devices present.
.\" ==========
.It Fl o
Display old-style
.Nm iostat
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 U
Display system load averages.
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.
.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 iostat
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 iostat
will display the smaller of the
requested number of devices, and the maximum number of devices in the system.
To force
.Nm iostat
to display specific drives, their names may be supplied on the command
line.
.Nm iostat
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 iostat
will show only the specified devices.
.Pp
The standard
.Nm iostat
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 iostat
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 iostat
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 iostat
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 iostat
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
34d340d7 A	72	.Nm iostat
34d340d7 A	73	.Op Fl CUdKIoT?\&
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
34d340d7 A	90	.\" ==========
	91	.It Fl ?\&
	92	Display a usage statement and exit.
	93	.\" ==========
	94	.It Fl C
	95	Display CPU statistics.
	96	This is on by default, unless
	97	.Fl d
	98	is specified.
	99	.\" ==========
1815bff5 A	100	.It Fl c
	101	Repeat the display
	102	.Ar count
	103	times.
1815bff5 A	104	If no
	105	.Ar wait
	106	interval is specified, the default is 1 second.
34d340d7	107	.\" ==========
b51d5b5f A	108	.It Fl d
	109	Display only device statistics.
	110	If this flag is turned on, only device statistics will be displayed, unless
	111	.Fl C
	112	or
34d340d7 A	113	.Fl U
34d340d7 A	114	or
b51d5b5f	115	.Fl T
34d340d7 A	116	is also specfied to enable the display of CPU, load average or TTY statistics.
34d340d7 A	117	.\" ==========
b51d5b5f A	118	.It Fl I
	119	Display total statstics for a given time period, rather than average
	120	statistics for each second during that time period.
34d340d7	121	.\" ==========
b51d5b5f	122	.It Fl K
20e66415	123	In the blocks transferred display (-o), display block count in kilobytes rather
b51d5b5f	124	then the device native block size.
34d340d7	125	.\" ==========
b51d5b5f A	126	.It Fl n
	127	Display up to
	128	.Ar devs
	129	number of devices.
34d340d7	130	.Nm iostat
b51d5b5f A	131	will display fewer devices if there aren't
	132	.Ar devs
	133	devices present.
34d340d7	134	.\" ==========
b51d5b5f A	135	.It Fl o
b51d5b5f A	136	Display old-style
34d340d7	137	.Nm iostat
b51d5b5f A	138	device statistics.
	139	Sectors per second, transfers per second, and miliseconds per seek are
	140	displayed.
	141	If
	142	.Fl I
	143	is specified, total blocks/sectors, total transfers, and
	144	miliseconds per seek are displayed.
34d340d7	145	.\" ==========
b51d5b5f A	146	.It Fl T
	147	Display TTY statistics.
	148	This is on by default, unless
	149	.Fl d
	150	is specified.
34d340d7 A	151	.\" ==========
	152	.It Fl U
	153	Display system load averages.
	154	This is on by default, unless
	155	.Fl d
	156	is specified.
	157	.\" ==========
1815bff5 A	158	.It Fl w
	159	Pause
	160	.Ar wait
	161	seconds between each display.
	162	If no repeat
	163	.Ar count
	164	is specified, the default is infinity.
	165	.El
	166	.Pp
	167	.Nm Iostat
	168	displays its information in the following format:
	169	.Bl -tag -width flag
	170	.It tty
	171	.Bl -tag -width indent -compact
	172	.It tin
	173	characters read from terminals
	174	.It tout
	175	characters written to terminals
	176	.El
b51d5b5f A	177	.It devices
	178	Device operations.
	179	The header of the field is the device name and unit number.
34d340d7	180	.Nm iostat
b51d5b5f A	181	will display as many devices as will fit in a standard 80 column screen, or
	182	the maximum number of devices in the system, whichever is smaller.
	183	If
	184	.Fl n
	185	is specified on the command line,
34d340d7	186	.Nm iostat
b51d5b5f A	187	will display the smaller of the
b51d5b5f A	188	requested number of devices, and the maximum number of devices in the system.
1815bff5	189	To force
34d340d7	190	.Nm iostat
1815bff5 A	191	to display specific drives, their names may be supplied on the command
1815bff5 A	192	line.
34d340d7	193	.Nm iostat
b51d5b5f A	194	will not display more devices than will fit in an 80 column screen, unless
	195	the
	196	.Fl n
	197	argument is given on the command line to specify a maximum number of
	198	devices to display, or the list of specified devices exceeds 80 columns.
	199	If fewer devices are specified on the command line than will fit in an 80
	200	column screen,
34d340d7	201	.Nm iostat
b51d5b5f A	202	will show only the specified devices.
	203	.Pp
	204	The standard
34d340d7	205	.Nm iostat
b51d5b5f A	206	device display shows the following statistics:
	207	.Pp
	208	.Bl -tag -width indent -compact
	209	.It KB/t
	210	kilobytes per transfer
	211	.It tps
	212	transfers per second
	213	.It MB/s
	214	megabytes per second
	215	.El
	216	.Pp
	217	The standard
34d340d7	218	.Nm iostat
b51d5b5f A	219	device display, with the
	220	.Fl I
	221	flag specified, shows the following statistics:
	222	.Pp
	223	.Bl -tag -width indent -compact
	224	.It KB/t
	225	kilobytes per transfer
	226	.It xfrs
	227	total number of transfers
	228	.It MB
	229	total number of megabytes transferred
	230	.El
	231	.Pp
	232	The old-style
34d340d7	233	.Nm iostat
b51d5b5f A	234	display (using
	235	.Fl o )
	236	shows the following statistics:
1815bff5 A	237	.Pp
	238	.Bl -tag -width indent -compact
	239	.It sps
	240	sectors transferred per second
	241	.It tps
	242	transfers per second
	243	.It msps
b51d5b5f A	244	average milliseconds per transaction
	245	.El
	246	.Pp
	247	The old-style
34d340d7	248	.Nm iostat
b51d5b5f A	249	display, with the
	250	.Fl I
	251	flag specified, shows the following statistics:
	252	.Pp
	253	.Bl -tag -width indent -compact
	254	.It blk
	255	total blocks/sectors transferred
	256	.It xfr
	257	total transfers
	258	.It msps
	259	average milliseconds per transaction
1815bff5 A	260	.El
	261	.It cpu
	262	.Bl -tag -width indent -compact
	263	.It \&us
	264	% of cpu time in user mode
1815bff5 A	265	.It \&sy
	266	% of cpu time in system mode
	267	.It \&id
	268	% of cpu time in idle mode
	269	.El
	270	.El
b51d5b5f A	271	.Sh EXAMPLES
	272	.Dl iostat -w 1 disk0 disk2
	273	.Pp
	274	Display statistics for the first and third disk devices device every
	275	second ad infinitum.
	276	.Pp
	277	.Dl iostat -c 2
	278	.Pp
	279	Display the statistics for the first four devices in the system twice, with
	280	a one second display interval.
	281	.Pp
	282	.Dl iostat -Iw 3
	283	.Pp
	284	Display total statistics every three seconds ad infinitum.
	285	.Pp
	286	.Dl iostat -odICTw 2 -c 9
	287	.Pp
	288	Display total statistics using the old-style output format 9 times, with
	289	a two second interval between each measurement/display.
	290	The
	291	.Fl d
	292	flag generally disables the TTY and CPU displays, but since the
	293	.Fl T
	294	and
	295	.Fl C
	296	flags are given, the TTY and CPU displays will be displayed.
1815bff5 A	297	.Sh SEE ALSO
	298	.Xr fstat 1 ,
	299	.Xr netstat 1 ,
	300	.Xr nfsstat 1 ,
b51d5b5f	301	.Xr ps 1 ,
34d340d7	302	.Xr pstat 8
1815bff5 A	303	.Pp
	304	The sections starting with ``Interpreting system activity'' in
	305	.%T "Installing and Operating 4.3BSD" .
b51d5b5f A	306	.Sh HISTORY
b51d5b5f A	307	This version of
34d340d7	308	.Nm iostat
b51d5b5f A	309	first appeared in
b51d5b5f A	310	.Nm FreeBSD 3.0 .