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.\" $FreeBSD$ 34.\" 35.Dd June 6, 1996 36.Dt VMSTAT 8 37.Os 38.Sh NAME 39.Nm vmstat 40.Nd report virtual memory statistics 41.Sh SYNOPSIS 42.Nm 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.Oo 51.Fl p 52.Sm off 53.Ar type , if , pass 54.Sm on 55.Oc 56.Op Ar disks 57.Sh DESCRIPTION 58.Nm Vmstat 59reports certain kernel statistics kept about process, virtual memory, 60disk, trap and cpu activity. 61.Pp 62The options are as follows: 63.Bl -tag -width indent 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 /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 p 101Specify which types of devices to display. There are three different 102categories of devices: 103.Pp 104.Bl -tag -width indent -compact 105.It device type: 106.Bl -tag -width 9n -compact 107.It da 108Direct Access devices 109.It sa 110Sequential Access devices 111.It printer 112Printers 113.It proc 114Processor devices 115.It worm 116Write Once Read Multiple devices 117.It cd 118CD devices 119.It scanner 120Scanner devices 121.It optical 122Optical Memory devices 123.It changer 124Medium Changer devices 125.It comm 126Communication devices 127.It array 128Storage Array devices 129.It enclosure 130Enclosure Services devices 131.It floppy 132Floppy devices 133.El 134.Pp 135.It interface: 136.Bl -tag -width 9n -compact 137.It IDE 138Integrated Drive Electronics devices 139.It SCSI 140Small Computer System Interface devices 141.It other 142Any other device interface 143.El 144.Pp 145.It passthrough: 146.Bl -tag -width 9n -compact 147.It pass 148Passthrough devices 149.El 150.El 151.Pp 152The user must specify at least one device type, and may specify at most 153one device type from each category. Multiple device types in a single 154device type statement must be separated by commas. 155.Pp 156Any number of 157.Fl p 158arguments may be specified on the command line. All 159.Fl p 160arguments are ORed together to form a matching expression against which 161all devices in the system are compared. Any device that fully matches 162any 163.Fl p 164argument will be included in the 165.Nm 166output, up to three devices, or the maximum number of devices specified 167by the user. 168.It Fl s 169Display the contents of the 170.Em sum 171structure, giving the total number of several kinds of paging related 172events which have occurred since system startup. 173.\" .It Fl t 174.\" Report on the number of page in and page reclaims since system startup, 175.\" and the amount of time required by each. 176.It Fl w 177Pause 178.Ar wait 179seconds between each display. 180If no repeat 181.Ar wait 182interval is specified, the default is 1 second. 183.It Fl z 184Report on memory used by the kernel zone allocator, by zone. 185The information shown is the same as that returned by the 186.Va vm.zone 187sysctl variable. 188.El 189.Pp 190By default, 191.Nm 192displays the following information: 193.Pp 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 avm 214active virtual pages 215.It fre 216size of the free list 217.El 218.It page 219Information about page faults and paging activity. 220These are averaged each five seconds, and given in units per second. 221.Pp 222.Bl -tag -width indent -compact 223.It flt 224total number of page faults 225.It re 226page reclaims (simulating reference bits) 227.\" .It at 228.\" pages attached (found in free list) 229.It pi 230pages paged in 231.It po 232pages paged out 233.It fr 234pages freed per second 235.\" .It de 236.\" anticipated short term memory shortfall 237.It sr 238pages scanned by clock algorithm, per-second 239.El 240.It disks 241Disk operations per second (this field is system dependent). 242Typically paging will be split across the available drives. 243The header of the field is the first two characters of the disk name and 244the unit number. 245If more than three disk drives are configured in the system, 246.Nm 247displays only the first three drives, unless the user specifies the 248.Fl n 249argument to increase the number of drives displayed. This will probably 250cause the display to exceed 80 columns, however. 251To force 252.Nm 253to display specific drives, their names may be supplied on the command line. 254.Nm 255defaults to show disks first, and then various other random devices in the 256system to add up to three devices, if there are that many devices in the 257system. If devices are specified on the command line, or if a device type 258matching pattern is specified (see above), 259.Nm 260will only display the given devices or the devices matching the pattern, 261and will not randomly select other devices in the system. 262.It faults 263Trap/interrupt rate averages per second over last 5 seconds. 264.Pp 265.Bl -tag -width indent -compact 266.It in 267device interrupts per interval (including clock interrupts) 268.It sy 269system calls per interval 270.It cs 271cpu context switch rate (switches/interval) 272.El 273.It cpu 274Breakdown of percentage usage of CPU time. 275.Pp 276.Bl -tag -width indent -compact 277.It us 278user time for normal and low priority processes 279.It sy 280system time 281.It id 282cpu idle 283.El 284.El 285.Sh EXAMPLES 286The command: 287.Dl vmstat -w 5 288will print what the system is doing every five 289seconds; this is a good choice of printing interval since this is how often 290some of the statistics are sampled in the system. 291Others vary every second and running the output for a while will make it 292apparent which are recomputed every second. 293.Pp 294The command: 295.Dl vmstat -p da -p cd -w 1 296will tell vmstat to select the first three direct access or CDROM devices 297and display statistics on those devices, as well as other systems 298statistics every second. 299.Sh FILES 300.Bl -tag -width /dev/kmemxxx -compact 301.It Pa /kernel 302default kernel namelist 303.It Pa /dev/kmem 304default memory file 305.El 306.Sh SEE ALSO 307.Xr fstat 1 , 308.Xr netstat 1 , 309.Xr nfsstat 1 , 310.Xr ps 1 , 311.Xr systat 1 , 312.Xr iostat 8 , 313.Xr pstat 8 , 314.Xr sysctl 8 315.Pp 316The sections starting with ``Interpreting system activity'' in 317.%T "Installing and Operating 4.3BSD" . 318.Sh BUGS 319The 320.Fl c 321and 322.Fl w 323options are only available with the default output. 324