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.\" $FreeBSD: src/usr.bin/vmstat/vmstat.8,v 1.16.2.5 2001/08/16 13:17:13 ru Exp $ 34.\" $DragonFly: src/usr.bin/vmstat/vmstat.8,v 1.3 2006/02/17 19:39:15 swildner Exp $ 35.\" 36.Dd June 6, 1996 37.Dt VMSTAT 8 38.Os 39.Sh NAME 40.Nm vmstat 41.Nd report virtual memory statistics 42.Sh SYNOPSIS 43.Nm 44.\" .Op Fl fimst 45.Op Fl imsz 46.Op Fl c Ar count 47.Op Fl M Ar core 48.Op Fl N Ar system 49.Op Fl w Ar wait 50.Op Fl n Ar devs 51.Oo 52.Fl p 53.Sm off 54.Ar type , if , pass 55.Sm on 56.Oc 57.Op Ar disks 58.Sh DESCRIPTION 59.Nm Vmstat 60reports certain kernel statistics kept about process, virtual memory, 61disk, trap and cpu activity. 62.Pp 63The options are as follows: 64.Bl -tag -width indent 65.It Fl c 66Repeat the display 67.Ar count 68times. 69The first display is for the time since a reboot and each subsequent 70report is for the time period since the last display. 71If no repeat 72.Ar count 73is specified, and 74.Fl w 75is specified, the default is infinity, otherwise the default is one. 76.\" .It Fl f 77.\" Report on the number 78.\" .Xr fork 2 79.\" and 80.\" .Xr vfork 2 81.\" system calls since system startup, and the number of pages of virtual memory 82.\" involved in each. 83.It Fl i 84Report on the number of interrupts taken by each device since system 85startup. 86.It Fl M 87Extract values associated with the name list from the specified 88.Ar core 89instead of the default 90.Pa /dev/kmem . 91.It Fl N 92Extract the name list from the specified 93.Ar system 94instead of the default 95.Pa /kernel . 96.It Fl m 97Report on the usage of kernel dynamic memory listed first by size of 98allocation and then by type of usage. 99.It Fl n 100Change the maximum number of disks to display from the default of 2. 101.It Fl p 102Specify which types of devices to display. There are three different 103categories of devices: 104.Pp 105.Bl -tag -width indent -compact 106.It device type: 107.Bl -tag -width 9n -compact 108.It da 109Direct Access devices 110.It sa 111Sequential Access devices 112.It printer 113Printers 114.It proc 115Processor devices 116.It worm 117Write Once Read Multiple devices 118.It cd 119CD devices 120.It scanner 121Scanner devices 122.It optical 123Optical Memory devices 124.It changer 125Medium Changer devices 126.It comm 127Communication devices 128.It array 129Storage Array devices 130.It enclosure 131Enclosure Services devices 132.It floppy 133Floppy devices 134.El 135.Pp 136.It interface: 137.Bl -tag -width 9n -compact 138.It IDE 139Integrated Drive Electronics devices 140.It SCSI 141Small Computer System Interface devices 142.It other 143Any other device interface 144.El 145.Pp 146.It passthrough: 147.Bl -tag -width 9n -compact 148.It pass 149Passthrough devices 150.El 151.El 152.Pp 153The user must specify at least one device type, and may specify at most 154one device type from each category. Multiple device types in a single 155device type statement must be separated by commas. 156.Pp 157Any number of 158.Fl p 159arguments may be specified on the command line. All 160.Fl p 161arguments are ORed together to form a matching expression against which 162all devices in the system are compared. Any device that fully matches 163any 164.Fl p 165argument will be included in the 166.Nm 167output, up to three devices, or the maximum number of devices specified 168by the user. 169.It Fl s 170Display the contents of the 171.Em sum 172structure, giving the total number of several kinds of paging related 173events which have occurred since system startup. 174.\" .It Fl t 175.\" Report on the number of page in and page reclaims since system startup, 176.\" and the amount of time required by each. 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.Pp 195.Bl -tag -width indent 196.It procs 197Information about the numbers of processes in various states. 198.Pp 199.Bl -tag -width indent -compact 200.It r 201in run queue 202.It b 203blocked for resources (i/o, paging, etc.) 204.It w 205runnable or short sleeper (< 20 secs) but swapped 206.El 207.It memory 208Information about the usage of virtual and real memory. 209Virtual pages (reported in units of 1024 bytes) are considered active if 210they belong to processes which are running or have run in the last 20 211seconds. 212.Pp 213.Bl -tag -width indent -compact 214.It avm 215active virtual pages 216.It fre 217size of the free list 218.El 219.It page 220Information about page faults and paging activity. 221These are averaged each five seconds, and given in units per second. 222.Pp 223.Bl -tag -width indent -compact 224.It flt 225total number of page faults 226.It re 227page reclaims (simulating reference bits) 228.\" .It at 229.\" pages attached (found in free list) 230.It pi 231pages paged in 232.It po 233pages paged out 234.It fr 235pages freed per second 236.\" .It de 237.\" anticipated short term memory shortfall 238.It sr 239pages scanned by clock algorithm, per-second 240.El 241.It disks 242Disk operations per second (this field is system dependent). 243Typically paging will be split across the available drives. 244The header of the field is the first two characters of the disk name and 245the unit number. 246If more than three disk drives are configured in the system, 247.Nm 248displays only the first three drives, unless the user specifies the 249.Fl n 250argument to increase the number of drives displayed. This will probably 251cause the display to exceed 80 columns, however. 252To force 253.Nm 254to display specific drives, their names may be supplied on the command line. 255.Nm 256defaults to show disks first, and then various other random devices in the 257system to add up to three devices, if there are that many devices in the 258system. If devices are specified on the command line, or if a device type 259matching pattern is specified (see above), 260.Nm 261will only display the given devices or the devices matching the pattern, 262and will not randomly select other devices in the system. 263.It faults 264Trap/interrupt rate averages per second over last 5 seconds. 265.Pp 266.Bl -tag -width indent -compact 267.It in 268device interrupts per interval (including clock interrupts) 269.It sy 270system calls per interval 271.It cs 272cpu context switch rate (switches/interval) 273.El 274.It cpu 275Breakdown of percentage usage of CPU time. 276.Pp 277.Bl -tag -width indent -compact 278.It us 279user time for normal and low priority processes 280.It sy 281system time 282.It id 283cpu idle 284.El 285.El 286.Sh FILES 287.Bl -tag -width /dev/kmemxxx -compact 288.It Pa /kernel 289default kernel namelist 290.It Pa /dev/kmem 291default memory file 292.El 293.Sh EXAMPLES 294The command: 295.Dl vmstat -w 5 296will print what the system is doing every five 297seconds; this is a good choice of printing interval since this is how often 298some of the statistics are sampled in the system. 299Others vary every second and running the output for a while will make it 300apparent which are recomputed every second. 301.Pp 302The command: 303.Dl vmstat -p da -p cd -w 1 304will tell vmstat to select the first three direct access or CDROM devices 305and display statistics on those devices, as well as other systems 306statistics every second. 307.Sh SEE ALSO 308.Xr fstat 1 , 309.Xr netstat 1 , 310.Xr nfsstat 1 , 311.Xr ps 1 , 312.Xr systat 1 , 313.Xr iostat 8 , 314.Xr pstat 8 , 315.Xr sysctl 8 316.Pp 317The sections starting with ``Interpreting system activity'' in 318.%T "Installing and Operating 4.3BSD" . 319.Sh BUGS 320The 321.Fl c 322and 323.Fl w 324options are only available with the default output. 325