1 .\" Copyright (c) 1986, 1993
2 .\" The Regents of the University of California. All rights reserved.
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5 .\" modification, are permitted provided that the following conditions
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14 .\" This product includes software developed by the University of
15 .\" California, Berkeley and its contributors.
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20 .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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23 .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 .\" @(#)vmstat.8 8.1 (Berkeley) 6/6/93
33 .\" $FreeBSD: src/usr.bin/vmstat/vmstat.8,v 1.16.2.5 2001/08/16 13:17:13 ru Exp $
40 .Nd report virtual memory statistics
59 reports certain kernel statistics kept about process, virtual memory,
60 disk, trap and cpu activity.
62 The options are as follows:
63 .Bl -tag -width indent
68 The first display is for the time since a reboot and each subsequent
69 report is for the time period since the last display.
74 is specified, the default is infinity, otherwise the default is one.
76 .\" Report on the number
80 .\" system calls since system startup, and the number of pages of virtual memory
83 Report on the number of interrupts taken by each device since system
86 Extract values associated with the name list from the specified
88 instead of the default
91 Extract the name list from the specified
93 instead of the default
96 Report on the usage of kernel dynamic memory listed first by size of
97 allocation and then by type of usage.
99 Change the maximum number of disks to display from the default of 2.
101 Specify which types of devices to display. There are three different
102 categories of devices:
104 .Bl -tag -width indent -compact
106 .Bl -tag -width 9n -compact
108 Direct Access devices
110 Sequential Access devices
116 Write Once Read Multiple devices
122 Optical Memory devices
124 Medium Changer devices
126 Communication devices
128 Storage Array devices
130 Enclosure Services devices
136 .Bl -tag -width 9n -compact
138 Integrated Drive Electronics devices
140 Small Computer System Interface devices
142 Any other device interface
146 .Bl -tag -width 9n -compact
152 The user must specify at least one device type, and may specify at most
153 one device type from each category. Multiple device types in a single
154 device type statement must be separated by commas.
158 arguments may be specified on the command line. All
160 arguments are ORed together to form a matching expression against which
161 all devices in the system are compared. Any device that fully matches
164 argument will be included in the
166 output, up to three devices, or the maximum number of devices specified
169 Display the contents of the
171 structure, giving the total number of several kinds of paging related
172 events which have occurred since system startup.
174 .\" Report on the number of page in and page reclaims since system startup,
175 .\" and the amount of time required by each.
179 seconds between each display.
182 interval is specified, the default is 1 second.
184 Report on memory used by the kernel zone allocator, by zone.
185 The information shown is the same as that returned by the
192 displays the following information:
194 .Bl -tag -width indent
196 Information about the numbers of processes in various states.
198 .Bl -tag -width indent -compact
202 blocked for resources (i/o, paging, etc.)
204 runnable or short sleeper (< 20 secs) but swapped
207 Information about the usage of virtual and real memory.
208 Virtual pages (reported in units of 1024 bytes) are considered active if
209 they belong to processes which are running or have run in the last 20
212 .Bl -tag -width indent -compact
216 size of the free list
219 Information about page faults and paging activity.
220 These are averaged each five seconds, and given in units per second.
222 .Bl -tag -width indent -compact
224 total number of page faults
226 page reclaims (simulating reference bits)
228 .\" pages attached (found in free list)
234 pages freed per second
236 .\" anticipated short term memory shortfall
238 pages scanned by clock algorithm, per-second
241 Disk operations per second (this field is system dependent).
242 Typically paging will be split across the available drives.
243 The header of the field is the first two characters of the disk name and
245 If more than three disk drives are configured in the system,
247 displays only the first three drives, unless the user specifies the
249 argument to increase the number of drives displayed. This will probably
250 cause the display to exceed 80 columns, however.
253 to display specific drives, their names may be supplied on the command line.
255 defaults to show disks first, and then various other random devices in the
256 system to add up to three devices, if there are that many devices in the
257 system. If devices are specified on the command line, or if a device type
258 matching pattern is specified (see above),
260 will only display the given devices or the devices matching the pattern,
261 and will not randomly select other devices in the system.
263 Trap/interrupt rate averages per second over last 5 seconds.
265 .Bl -tag -width indent -compact
267 device interrupts per interval (including clock interrupts)
269 system calls per interval
271 cpu context switch rate (switches/interval)
274 Breakdown of percentage usage of CPU time.
276 .Bl -tag -width indent -compact
278 user time for normal and low priority processes
288 will print what the system is doing every five
289 seconds; this is a good choice of printing interval since this is how often
290 some of the statistics are sampled in the system.
291 Others vary every second and running the output for a while will make it
292 apparent which are recomputed every second.
295 .Dl vmstat -p da -p cd -w 1
296 will tell vmstat to select the first three direct access or CDROM devices
297 and display statistics on those devices, as well as other systems
298 statistics every second.
300 .Bl -tag -width /dev/kmemxxx -compact
302 default kernel namelist
316 The sections starting with ``Interpreting system activity'' in
317 .%T "Installing and Operating 4.3BSD" .
323 options are only available with the default output.