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 fimst 41.Op Fl imsvz 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 c 62Repeat the display 63.Ar count 64times. 65The first display is for the time since a reboot and each subsequent 66report is for the time period since the last display. 67If no repeat 68.Ar count 69is specified, and 70.Fl w 71is specified, the default is infinity, otherwise the default is one. 72.\" .It Fl f 73.\" Report on the number 74.\" .Xr fork 2 75.\" and 76.\" .Xr vfork 2 77.\" system calls since system startup, and the number of pages of virtual memory 78.\" involved in each. 79.It Fl i 80Report on the number of interrupts taken by each device since system 81startup. 82.It Fl M 83Extract values associated with the name list from the specified 84.Ar core 85instead of the default 86.Pa /dev/kmem . 87.It Fl N 88Extract the name list from the specified 89.Ar system 90instead of the default 91.Pa /boot/kernel . 92.It Fl m 93Report on the usage of kernel dynamic memory listed first by size of 94allocation and then by type of usage. 95.It Fl n 96Change the maximum number of disks to display from the default of 2. 97.It Fl p 98Specify which types of devices to display. There are three different 99categories of devices: 100.Pp 101.Bl -tag -width indent -compact 102.It device type: 103.Bl -tag -width 9n -compact 104.It da 105Direct Access devices 106.It sa 107Sequential Access devices 108.It printer 109Printers 110.It proc 111Processor devices 112.It worm 113Write Once Read Multiple devices 114.It cd 115CD devices 116.It scanner 117Scanner devices 118.It optical 119Optical Memory devices 120.It changer 121Medium Changer devices 122.It comm 123Communication devices 124.It array 125Storage Array devices 126.It enclosure 127Enclosure Services devices 128.It floppy 129Floppy devices 130.El 131.Pp 132.It interface: 133.Bl -tag -width 9n -compact 134.It IDE 135Integrated Drive Electronics devices 136.It SCSI 137Small Computer System Interface devices 138.It other 139Any other device interface 140.El 141.Pp 142.It passthrough: 143.Bl -tag -width 9n -compact 144.It pass 145Passthrough devices 146.El 147.El 148.Pp 149The user must specify at least one device type, and may specify at most 150one device type from each category. Multiple device types in a single 151device type statement must be separated by commas. 152.Pp 153Any number of 154.Fl p 155arguments may be specified on the command line. All 156.Fl p 157arguments are ORed together to form a matching expression against which 158all devices in the system are compared. Any device that fully matches 159any 160.Fl p 161argument will be included in the 162.Nm 163output, up to three devices, or the maximum number of devices specified 164by the user. 165.It Fl s 166Display the contents of the 167.Em sum 168structure, giving the total number of several kinds of paging related 169events which have occurred since system startup. 170.\" .It Fl t 171.\" Report on the number of page in and page reclaims since system startup, 172.\" and the amount of time required by each. 173.It Fl v 174If specified together with 175.Fl i , 176include IRQ numbers and IRQ target CPU numbers before device names. 177.It Fl w 178Pause 179.Ar wait 180seconds between each display. 181If no repeat 182.Ar wait 183interval is specified, the default is 1 second. 184.It Fl z 185Report on memory used by the kernel zone allocator, by zone. 186The information shown is the same as that returned by the 187.Va vm.zone 188sysctl variable. 189.El 190.Pp 191By default, 192.Nm 193displays the following information: 194.Bl -tag -width indent 195.It procs 196Information about the numbers of processes in various states. 197.Pp 198.Bl -tag -width indent -compact 199.It r 200in run queue 201.It b 202blocked for resources (i/o, paging, etc.) 203.It w 204runnable or short sleeper (< 20 secs) but swapped 205.El 206.It memory 207Information about the usage of virtual and real memory. 208Virtual pages (reported in units of 1024 bytes) are considered active if 209they belong to processes which are running or have run in the last 20 210seconds. 211.Pp 212.Bl -tag -width indent -compact 213.It fre 214Approximate free and easily-freeable memory. 215.El 216.It page 217Information about page faults and paging activity. 218These are averaged each five seconds, and given in units per second. 219.Pp 220.Bl -tag -width indent -compact 221.It flt 222total number of page faults 223.It re 224page reclaims (simulating reference bits) 225.\" .It at 226.\" pages attached (found in free list) 227.It pi 228pages paged in 229.It po 230pages paged out 231.It fr 232pages freed per second 233.\" .It de 234.\" anticipated short term memory shortfall 235.El 236.It disks 237Disk operations per second (this field is system dependent). 238Typically paging will be split across the available drives. 239The header of the field is the first two characters of the disk name and 240the unit number. 241If more than three disk drives are configured in the system, 242.Nm 243displays only the first three drives, unless the user specifies the 244.Fl n 245argument to increase the number of drives displayed. This will probably 246cause the display to exceed 80 columns, however. 247To force 248.Nm 249to display specific drives, their names may be supplied on the command line. 250.Nm 251defaults to show disks first, and then various other random devices in the 252system to add up to three devices, if there are that many devices in the 253system. If devices are specified on the command line, or if a device type 254matching pattern is specified (see above), 255.Nm 256will only display the given devices or the devices matching the pattern, 257and will not randomly select other devices in the system. 258.It faults 259Trap/interrupt rate averages per second over last 5 seconds. 260.Pp 261.Bl -tag -width indent -compact 262.It int 263device interrupts per interval (including clock interrupts) 264.It sys 265system calls per interval 266.It ctx 267cpu context switch rate (switches/interval) 268.El 269.It cpu 270Breakdown of percentage usage of CPU time. 271.Pp 272.Bl -tag -width indent -compact 273.It us 274user time for normal and low priority processes 275.It sy 276system time 277.It id 278cpu idle 279.El 280.El 281.Sh FILES 282.Bl -tag -width /dev/kmemxxx -compact 283.It Pa /boot/kernel 284default kernel namelist 285.It Pa /dev/kmem 286default memory file 287.El 288.Sh EXAMPLES 289The command: 290.Dl vmstat -w 5 291will print what the system is doing every five 292seconds; this is a good choice of printing interval since this is how often 293some of the statistics are sampled in the system. 294Others vary every second and running the output for a while will make it 295apparent which are recomputed every second. 296.Pp 297The command: 298.Dl vmstat -p da -p cd -w 1 299will tell vmstat to select the first three direct access or CDROM devices 300and display statistics on those devices, as well as other systems 301statistics every second. 302.Sh SEE ALSO 303.Xr fstat 1 , 304.Xr netstat 1 , 305.Xr nfsstat 1 , 306.Xr ps 1 , 307.Xr systat 1 , 308.Xr iostat 8 , 309.Xr pstat 8 , 310.Xr sysctl 8 311.Pp 312The sections starting with ``Interpreting system activity'' in 313.%T "Installing and Operating 4.3BSD" . 314.Sh BUGS 315The 316.Fl c 317and 318.Fl w 319options are only available with the default output. 320