2 .\" Copyright (c) 1997 Kenneth D. Merry.
3 .\" All rights reserved.
5 .\" Redistribution and use in source and binary forms, with or without
6 .\" modification, are permitted provided that the following conditions
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.
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
28 .\" $FreeBSD: src/usr.sbin/iostat/iostat.8,v 1.11.2.9 2002/12/29 16:35:41 schweikh Exp $
29 .\" $DragonFly: src/usr.sbin/iostat/iostat.8,v 1.2 2003/06/17 04:29:55 dillon Exp $
31 .\" Copyright (c) 1985, 1991, 1993
32 .\" The Regents of the University of California. All rights reserved.
34 .\" Redistribution and use in source and binary forms, with or without
35 .\" modification, are permitted provided that the following conditions
37 .\" 1. Redistributions of source code must retain the above copyright
38 .\" notice, this list of conditions and the following disclaimer.
39 .\" 2. Redistributions in binary form must reproduce the above copyright
40 .\" notice, this list of conditions and the following disclaimer in the
41 .\" documentation and/or other materials provided with the distribution.
42 .\" 3. All advertising materials mentioning features or use of this software
43 .\" must display the following acknowledgement:
44 .\" This product includes software developed by the University of
45 .\" California, Berkeley and its contributors.
46 .\" 4. Neither the name of the University nor the names of its contributors
47 .\" may be used to endorse or promote products derived from this software
48 .\" without specific prior written permission.
50 .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
51 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
52 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
53 .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
54 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
55 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
56 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
57 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
58 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
59 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
62 .\" @(#)iostat.8 8.1 (Berkeley) 6/6/93
91 statistics on terminal, device and cpu
94 The options are as follows:
102 interval is specified, the default is 1 second.
104 Display CPU statistics.
105 This is on by default, unless
109 Display only device statistics.
110 If this flag is turned on, only device statistics will be displayed, unless
114 is also specified to enable the display of CPU or TTY statistics.
123 will show devices in order from highest to lowest bytes
124 per measurement cycle.
126 Display total statistics for a given time period, rather than average
127 statistics for each second during that time period.
129 In the blocks transferred display (-o), display block count in kilobytes rather
130 then the device native block size.
132 Extract values associated with the name list from the specified core
133 instead of the default
140 will display fewer devices if there aren't
144 Extract the name list from the specified system instead of the default
150 Sectors per second, transfers per second, and milliseconds per seek are
154 is specified, total blocks/sectors, total transfers, and
155 milliseconds per seek are displayed.
157 Specify which types of devices to display.
158 There are three different categories of devices:
160 .Bl -tag -width indent -compact
162 .Bl -tag -width 9n -compact
164 Direct Access devices
166 Sequential Access devices
172 Write Once Read Multiple devices
178 Optical Memory devices
180 Medium Changer devices
182 Communication devices
184 Storage Array devices
186 Enclosure Services devices
192 .Bl -tag -width 9n -compact
194 Integrated Drive Electronics devices
196 Small Computer System Interface devices
198 Any other device interface
202 .Bl -tag -width 9n -compact
208 The user must specify at least one device type, and may specify at most
209 one device type from each category.
210 Multiple device types in a single device type statement must be separated by
215 arguments may be specified on the command line.
218 arguments are ORed together to form a matching expression against which
219 all devices in the system are compared.
220 Any device that fully matches any
222 argument will be included in the
224 output, up to the number of devices that can be displayed in
225 80 columns, or the maximum number of devices specified by the user.
227 Display TTY statistics.
228 This is on by default, unless
234 seconds between each display.
237 is specified, the default is infinity.
239 Display a usage statement and exit.
243 displays its information in the following format:
246 .Bl -tag -width indent -compact
248 characters read from terminals
250 characters written to terminals
254 The header of the field is the device name and unit number.
256 will display as many devices as will fit in a standard 80 column screen, or
257 the maximum number of devices in the system, whichever is smaller.
260 is specified on the command line,
262 will display the smaller of the
263 requested number of devices, and the maximum number of devices in the system.
266 to display specific drives, their names may be supplied on the command
269 will not display more devices than will fit in an 80 column screen, unless
272 argument is given on the command line to specify a maximum number of
274 If fewer devices are specified on the command line than will fit in an 80
277 will show only the specified devices.
281 device display shows the following statistics:
283 .Bl -tag -width indent -compact
285 kilobytes per transfer
294 device display, with the
296 flag specified, shows the following statistics:
298 .Bl -tag -width indent -compact
300 kilobytes per transfer
302 total number of transfers
304 total number of megabytes transferred
311 shows the following statistics:
313 .Bl -tag -width indent -compact
315 sectors transferred per second
319 average milliseconds per transaction
326 flag specified, shows the following statistics:
328 .Bl -tag -width indent -compact
330 total blocks/sectors transferred
334 average milliseconds per transaction
337 .Bl -tag -width indent -compact
339 % of cpu time in user mode
341 % of cpu time in user mode running niced processes
343 % of cpu time in system mode
345 % of cpu time in interrupt mode
347 % of cpu time in idle mode
351 .Bl -tag -width /dev/kmem -compact
353 Default kernel namelist.
358 .Dl iostat -w 1 da0 da1 cd0
360 Display statistics for the first two Direct Access devices and the first
361 CDROM device every second ad infinitum.
365 Display the statistics for the first four devices in the system twice, with
366 a one second display interval.
368 .Dl iostat -t da -t cd -w 1
370 Display statistics for all CDROM and Direct Access devices every second
373 .Dl iostat -t da,scsi,pass -t cd,scsi,pass
375 Display statistics once for all SCSI passthrough devices that provide access
376 to either Direct Access or CDROM devices.
378 .Dl iostat -h -n 8 -w 1
380 Display up to 8 devices with the most I/O every second ad infinitum.
382 .Dl iostat -dh -t da -w 1
384 Omit the TTY and CPU displays, show devices in order of performance and
385 show only Direct Access devices every second ad infinitum.
389 Display total statistics every three seconds ad infinitum.
391 .Dl iostat -odICTw 2 -c 9
393 Display total statistics using the old-style output format 9 times, with
394 a two second interval between each measurement/display.
397 flag generally disables the TTY and CPU displays, but since the
401 flags are given, the TTY and CPU displays will be displayed.
411 The sections starting with ``Interpreting system activity'' in
412 .%T "Installing and Operating 4.3BSD" .
419 You cannot display device statistics for a non-running system, due to the
420 fact that the new device statistics interface is accessible only via
422 which does not provide a way to access non-running systems.
424 .An Kenneth Merry Aq ken@FreeBSD.org