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. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.\" @(#)vmstat.8 8.1 (Berkeley) 6/6/93 29.\" $FreeBSD: src/usr.bin/vmstat/vmstat.8,v 1.16.2.5 2001/08/16 13:17:13 ru Exp $ 30.\" $DragonFly: src/usr.bin/vmstat/vmstat.8,v 1.6 2008/09/02 11:50:46 matthias Exp $ 31.\" 32.Dd May 30, 2013 33.Dt VMSTAT 8 34.Os 35.Sh NAME 36.Nm vmstat 37.Nd report virtual memory statistics 38.Sh SYNOPSIS 39.Nm 40.\" .Op Fl bfimst 41.Op Fl imosuvz 42.Op Fl c Ar count 43.Op Fl M Ar core 44.Op Fl N Ar system 45.Op Fl w Ar wait 46.Op Fl n Ar devs 47.Oo 48.Fl p 49.Sm off 50.Ar type , if , pass 51.Sm on 52.Oc 53.Op Ar disks 54.Sh DESCRIPTION 55.Nm Vmstat 56reports certain kernel statistics kept about process, virtual memory, 57disk, trap and cpu activity. 58.Pp 59The options are as follows: 60.Bl -tag -width indent 61.It Fl b 62Formatted numbers use a brief format which some may find 63more readable with looped output. 64.It Fl c 65Repeat the display 66.Ar count 67times. 68The first display is for the time since a reboot and each subsequent 69report is for the time period since the last display. 70If no repeat 71.Ar count 72is specified, and 73.Fl w 74is specified, the default is infinity, otherwise the default is one. 75.\" .It Fl f 76.\" Report on the number 77.\" .Xr fork 2 78.\" and 79.\" .Xr vfork 2 80.\" system calls since system startup, and the number of pages of virtual memory 81.\" involved in each. 82.It Fl i 83Report on the number of interrupts taken by each device since system 84startup. 85.It Fl M 86Extract values associated with the name list from the specified 87.Ar core 88instead of the default 89.Pa /dev/kmem . 90.It Fl N 91Extract the name list from the specified 92.Ar system 93instead of the default 94.Pa /boot/kernel . 95.It Fl m 96Report on the usage of kernel dynamic memory listed first by size of 97allocation and then by type of usage. 98.It Fl n 99Change the maximum number of disks to display from the default of 2. 100.It Fl o 101Report the usage of kernel object cache. 102It only works on the running system. 103.It Fl p 104Specify which types of devices to display. There are three different 105categories of devices: 106.Pp 107.Bl -tag -width indent -compact 108.It device type: 109.Bl -tag -width 9n -compact 110.It da 111Direct Access devices 112.It sa 113Sequential Access devices 114.It printer 115Printers 116.It proc 117Processor devices 118.It worm 119Write Once Read Multiple devices 120.It cd 121CD devices 122.It scanner 123Scanner devices 124.It optical 125Optical Memory devices 126.It changer 127Medium Changer devices 128.It comm 129Communication devices 130.It array 131Storage Array devices 132.It enclosure 133Enclosure Services devices 134.It floppy 135Floppy devices 136.El 137.Pp 138.It interface: 139.Bl -tag -width 9n -compact 140.It IDE 141Integrated Drive Electronics devices 142.It SCSI 143Small Computer System Interface devices 144.It other 145Any other device interface 146.El 147.Pp 148.It passthrough: 149.Bl -tag -width 9n -compact 150.It pass 151Passthrough devices 152.El 153.El 154.Pp 155The user must specify at least one device type, and may specify at most 156one device type from each category. Multiple device types in a single 157device type statement must be separated by commas. 158.Pp 159Any number of 160.Fl p 161arguments may be specified on the command line. All 162.Fl p 163arguments are ORed together to form a matching expression against which 164all devices in the system are compared. Any device that fully matches 165any 166.Fl p 167argument will be included in the 168.Nm 169output, up to three devices, or the maximum number of devices specified 170by the user. 171.It Fl s 172Display the contents of the 173.Em sum 174structure, giving the total number of several kinds of paging related 175events which have occurred since system startup. 176.\" .It Fl t 177.\" Report on the number of page in and page reclaims since system startup, 178.\" and the amount of time required by each. 179.It Fl u 180Output unformatted numeric values, suitable for field extraction and 181numeric sorting. 182Columnar output will not be nicely aligned. 183.It Fl v 184If specified together with 185.Fl i , 186include IRQ numbers and IRQ target CPU numbers before device names. 187.It Fl w 188Pause 189.Ar wait 190seconds between each display. 191If no repeat 192.Ar wait 193interval is specified, the default is 1 second. 194.It Fl z 195Report on memory used by the kernel zone allocator, by zone. 196The information shown is the same as that returned by the 197.Va vm.zone 198sysctl variable. 199.El 200.Pp 201By default, 202.Nm 203displays the following information: 204.Bl -tag -width indent 205.It procs 206Information about the numbers of processes in various states. 207.Pp 208.Bl -tag -width indent -compact 209.It r 210in run queue 211.It b 212blocked for resources (i/o, paging, etc.) 213.It w 214runnable or short sleeper (< 20 secs) but swapped 215.El 216.It memory 217Information about the usage of virtual and real memory. 218Virtual pages (reported in units of 1024 bytes) are considered active if 219they belong to processes which are running or have run in the last 20 220seconds. 221.Pp 222.Bl -tag -width indent -compact 223.It fre 224Approximate free and easily-freeable memory. 225.El 226.It page 227Information about page faults and paging activity. 228These are averaged each five seconds, and given in units per second. 229.Pp 230.Bl -tag -width indent -compact 231.It flt 232total number of page faults 233.It re 234page reclaims (simulating reference bits) 235.\" .It at 236.\" pages attached (found in free list) 237.It pi 238pages paged in 239.It po 240pages paged out 241.It fr 242pages freed per second 243.\" .It de 244.\" anticipated short term memory shortfall 245.El 246.It disks 247Disk operations per second (this field is system dependent). 248Typically paging will be split across the available drives. 249The header of the field is the first two characters of the disk name and 250the unit number. 251If more than three disk drives are configured in the system, 252.Nm 253displays only the first three drives, unless the user specifies the 254.Fl n 255argument to increase the number of drives displayed. This will probably 256cause the display to exceed 80 columns, however. 257To force 258.Nm 259to display specific drives, their names may be supplied on the command line. 260.Nm 261defaults to show disks first, and then various other random devices in the 262system to add up to three devices, if there are that many devices in the 263system. If devices are specified on the command line, or if a device type 264matching pattern is specified (see above), 265.Nm 266will only display the given devices or the devices matching the pattern, 267and will not randomly select other devices in the system. 268.It faults 269Trap/interrupt rate averages per second over last 5 seconds. 270.Pp 271.Bl -tag -width indent -compact 272.It int 273device interrupts per interval (including clock interrupts) 274.It sys 275system calls per interval 276.It ctx 277cpu context switch rate (switches/interval) 278.El 279.It cpu 280Breakdown of percentage usage of CPU time. 281.Pp 282.Bl -tag -width indent -compact 283.It us 284user time for normal and low priority processes 285.It sy 286system time 287.It id 288cpu idle 289.El 290.El 291.Sh FILES 292.Bl -tag -width /dev/kmemxxx -compact 293.It Pa /boot/kernel 294default kernel namelist 295.It Pa /dev/kmem 296default memory file 297.El 298.Sh EXAMPLES 299The command: 300.Dl vmstat -w 5 301will print what the system is doing every five 302seconds; this is a good choice of printing interval since this is how often 303some of the statistics are sampled in the system. 304Others vary every second and running the output for a while will make it 305apparent which are recomputed every second. 306.Pp 307The command: 308.Dl vmstat -p da -p cd -w 1 309will tell vmstat to select the first three direct access or CDROM devices 310and display statistics on those devices, as well as other systems 311statistics every second. 312.Sh SEE ALSO 313.Xr fstat 1 , 314.Xr netstat 1 , 315.Xr nfsstat 1 , 316.Xr ps 1 , 317.Xr systat 1 , 318.Xr iostat 8 , 319.Xr pstat 8 , 320.Xr sysctl 8 321.Pp 322The sections starting with ``Interpreting system activity'' in 323.%T "Installing and Operating 4.3BSD" . 324.Sh BUGS 325The 326.Fl c 327and 328.Fl w 329options are only available with the default output. 330