1.\" Copyright (c) 1986, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 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 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 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 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)vmstat.8 8.1 (Berkeley) 6/6/93 33.\" $Id: vmstat.8,v 1.12 1999/02/13 09:59:24 dillon Exp $ 34.\" 35.Dd June 6, 1996 36.Dt VMSTAT 8 37.Os BSD 4 38.Sh NAME 39.Nm vmstat 40.Nd report virtual memory statistics 41.Sh SYNOPSIS 42.Nm vmstat 43.\" .Op Fl fimst 44.Op Fl imsz 45.Op Fl c Ar count 46.Op Fl M Ar core 47.Op Fl N Ar system 48.Op Fl w Ar wait 49.Op Fl n Ar devs 50.Op Fl p Ar type,if,pass 51.Op Ar disks 52.Sh DESCRIPTION 53.Nm Vmstat 54reports certain kernel statistics kept about process, virtual memory, 55disk, trap and cpu activity. 56.Pp 57The options are as follows: 58.Bl -tag -width indent 59.It Fl c 60Repeat the display 61.Ar count 62times. 63The first display is for the time since a reboot and each subsequent report 64is for the time period since the last display. 65If no 66.Ar wait 67interval is specified, the default is 1 second. 68.\" .It Fl f 69.\" Report on the number 70.\" .Xr fork 2 71.\" and 72.\" .Xr vfork 2 73.\" system calls since system startup, and the number of pages of virtual memory 74.\" involved in each. 75.It Fl i 76Report on the number of interrupts taken by each device since system 77startup. 78.It Fl M 79Extract values associated with the name list from the specified 80.Ar core 81instead of the default 82.Pa /dev/kmem . 83.It Fl N 84Extract the name list from the specified 85.Ar system 86instead of the default 87.Pa /kernel . 88.It Fl m 89Report on the usage of kernel dynamic memory listed first by size of 90allocation and then by type of usage. 91.It Fl n 92Change the maximum number of disks to display from the default of 2. 93.It Fl p 94Specify which types of devices to display. There are three different 95categories of devices: 96 97.Bl -tag -width indent -compact 98.It device type: 99.Bl -tag -width 123456789 -compact 100.It da 101Direct Access devices 102.It sa 103Sequential Access devices 104.It printer 105Printers 106.It proc 107Processor devices 108.It worm 109Write Once Read Multiple devices 110.It cd 111CD devices 112.It scanner 113Scanner devices 114.It optical 115Optical Memory devices 116.It changer 117Medium Changer devices 118.It comm 119Communication devices 120.It array 121Storage Array devices 122.It enclosure 123Enclosure Services devices 124.It floppy 125Floppy devices 126.El 127.Pp 128.It interface: 129.Bl -tag -width 123456789 -compact 130.It IDE 131Integrated Drive Electronics devices 132.It SCSI 133Small Computer System Interface devices 134.It other 135Any other device interface 136.El 137.Pp 138.It passthrough: 139.Bl -tag -width 123456789 -compact 140.It pass 141Passthrough devices 142.El 143.El 144.Pp 145The user must specify at least one device type, and may specify at most 146one device type from each category. Multiple device types in a single 147device type statement must be separated by commas. 148.Pp 149Any number of 150.Fl p 151arguments may be specified on the command line. All 152.Fl p 153arguments are ORed together to form a matching expression against which 154all devices in the system are compared. Any device that fully matches 155any 156.Fl p 157argument will be included in the 158.Nm 159output, up to three devices, or the maximum number of devices specified 160by the user. 161.It Fl s 162Display the contents of the 163.Em sum 164structure, giving the total number of several kinds of paging related 165events which have occurred since system startup. 166.\" .It Fl t 167.\" Report on the number of page in and page reclaims since system startup, 168.\" and the amount of time required by each. 169.It Fl w 170Pause 171.Ar wait 172seconds between each display. 173If no repeat 174.Ar count 175is specified, the default is infinity. 176.El 177.Pp 178By default, 179.Nm 180displays the following information: 181.Pp 182.Bl -tag -width indent 183.It procs 184Information about the numbers of processes in various states. 185.Pp 186.Bl -tag -width indent -compact 187.It r 188in run queue 189.It b 190blocked for resources (i/o, paging, etc.) 191.It w 192runnable or short sleeper (< 20 secs) but swapped 193.It Fl z 194Report on memory used by the kernel zone allocator, by zone. 195.El 196.It memory 197Information about the usage of virtual and real memory. 198Virtual pages (reported in units of 1024 bytes) are considered active if 199they belong to processes which are running or have run in the last 20 200seconds. 201.Pp 202.Bl -tag -width indent -compact 203.It avm 204active virtual pages 205.It fre 206size of the free list 207.El 208.It page 209Information about page faults and paging activity. 210These are averaged each five seconds, and given in units per second. 211.Pp 212.Bl -tag -width indent -compact 213.It flt 214total number of page faults 215.It re 216page reclaims (simulating reference bits) 217.\" .It at 218.\" pages attached (found in free list) 219.It pi 220pages paged in 221.It po 222pages paged out 223.It fr 224pages freed per second 225.\" .It de 226.\" anticipated short term memory shortfall 227.It sr 228pages scanned by clock algorithm, per-second 229.El 230.It disks 231Disk operations per second (this field is system dependent). 232Typically paging will be split across the available drives. 233The header of the field is the first two characters of the disk name and 234the unit number. 235If more than three disk drives are configured in the system, 236.Nm 237displays only the first three drives, unless the user specifies the 238.Fl n 239argument to increase the number of drives displayed. This will probably 240cause the display to exceed 80 columns, however. 241To force 242.Nm 243to display specific drives, their names may be supplied on the command line. 244.Nm 245defaults to show disks first, and then various other random devices in the 246system to add up to three devices, if there are that many devices in the 247system. If devices are specified on the command line, or if a device type 248matching pattern is specified (see above), 249.Nm 250will only display the given devices or the devices matching the pattern, 251and will not randomly select other devices in the system. 252.It faults 253Trap/interrupt rate averages per second over last 5 seconds. 254.Pp 255.Bl -tag -width indent -compact 256.It in 257device interrupts per interval (including clock interrupts) 258.It sy 259system calls per interval 260.It cs 261cpu context switch rate (switches/interval) 262.El 263.It cpu 264Breakdown of percentage usage of CPU time. 265.Pp 266.Bl -tag -width indent -compact 267.It us 268user time for normal and low priority processes 269.It sy 270system time 271.It id 272cpu idle 273.El 274.El 275.Sh EXAMPLES 276The command: 277.Dl vmstat -w 5 278will print what the system is doing every five 279seconds; this is a good choice of printing interval since this is how often 280some of the statistics are sampled in the system. 281Others vary every second and running the output for a while will make it 282apparent which are recomputed every second. 283.Pp 284The command: 285.Dl vmstat -p da -p cd -w 1 286will tell vmstat to select the first three direct access or CDROM devices 287and display statistics on those devices, as well as other systems 288statistics every second. 289.Sh FILES 290.Bl -tag -width /dev/kmemxxx -compact 291.It Pa /kernel 292default kernel namelist 293.It Pa /dev/kmem 294default memory file 295.El 296.Sh SEE ALSO 297.Xr fstat 1 , 298.Xr netstat 1 , 299.Xr nfsstat 1 , 300.Xr ps 1 , 301.Xr systat 1 , 302.Xr iostat 8 , 303.Xr pstat 8 304.Pp 305The sections starting with ``Interpreting system activity'' in 306.%T "Installing and Operating 4.3BSD" . 307.Sh BUGS 308The 309.Fl c 310and 311.Fl w 312options are only available with the default output. 313