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 December 10, 2003 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 afimsz 45.Op Fl c Ar count 46.Op Fl M Ar core Op Fl N Ar system 47.Op Fl w Ar wait 48.Op Fl n Ar devs 49.Oo 50.Fl p 51.Sm off 52.Ar type , if , pass 53.Sm on 54.Oc 55.Op Ar disks 56.Sh DESCRIPTION 57The 58.Nm 59utility reports certain kernel statistics kept about process, virtual memory, 60disk, trap and cpu activity. 61.Pp 62If the 63.Fl M 64option is not specified, information is obtained from 65the currently running kernel via the 66.Xr sysctl 3 67interface. 68Otherwise, information is read from the specified core file, 69using the name list from the specified kernel image (or from 70the default image). 71.Pp 72The options are as follows: 73.Bl -tag -width indent 74.It Fl a 75When used with 76.Fl i , 77include statistics about interrupts that have never been generated. 78.It Fl c 79Repeat the display 80.Ar count 81times. 82The first display is for the time since a reboot and each subsequent 83report is for the time period since the last display. 84If no repeat 85.Ar count 86is specified, and 87.Fl w 88is specified, the default is infinity, otherwise the default is one. 89.It Fl f 90Report on the number 91.Xr fork 2 , 92.Xr vfork 2 93and 94.Xr rfork 2 95system calls since system startup, and the number of pages of virtual memory 96involved in each. 97.It Fl i 98Report on the number of interrupts taken by each device since system 99startup. 100.It Fl M 101Extract values associated with the name list from the specified 102.Ar core . 103.It Fl N 104If 105.Fl M 106is also specified, 107extract the name list from the specified 108.Ar system 109instead of the default, 110which is the kernel image the system has booted from. 111.It Fl m 112Report on the usage of kernel dynamic memory listed first by size of 113allocation and then by type of usage. 114.It Fl n 115Change the maximum number of disks to display from the default of 2. 116.It Fl p 117Specify which types of devices to display. There are three different 118categories of devices: 119.Pp 120.Bl -tag -width indent -compact 121.It device type: 122.Bl -tag -width 9n -compact 123.It da 124Direct Access devices 125.It sa 126Sequential Access devices 127.It printer 128Printers 129.It proc 130Processor devices 131.It worm 132Write Once Read Multiple devices 133.It cd 134CD devices 135.It scanner 136Scanner devices 137.It optical 138Optical Memory devices 139.It changer 140Medium Changer devices 141.It comm 142Communication devices 143.It array 144Storage Array devices 145.It enclosure 146Enclosure Services devices 147.It floppy 148Floppy devices 149.El 150.Pp 151.It interface: 152.Bl -tag -width 9n -compact 153.It IDE 154Integrated Drive Electronics devices 155.It SCSI 156Small Computer System Interface devices 157.It other 158Any other device interface 159.El 160.Pp 161.It passthrough: 162.Bl -tag -width 9n -compact 163.It pass 164Passthrough devices 165.El 166.El 167.Pp 168The user must specify at least one device type, and may specify at most 169one device type from each category. Multiple device types in a single 170device type statement must be separated by commas. 171.Pp 172Any number of 173.Fl p 174arguments may be specified on the command line. All 175.Fl p 176arguments are ORed together to form a matching expression against which 177all devices in the system are compared. Any device that fully matches 178any 179.Fl p 180argument will be included in the 181.Nm 182output, up to three devices, or the maximum number of devices specified 183by the user. 184.It Fl s 185Display the contents of the 186.Em sum 187structure, giving the total number of several kinds of paging related 188events which have occurred since system startup. 189.\" .It Fl t 190.\" Report on the number of page in and page reclaims since system startup, 191.\" and the amount of time required by each. 192.It Fl w 193Pause 194.Ar wait 195seconds between each display. 196If no repeat 197.Ar wait 198interval is specified, the default is 1 second. 199.It Fl z 200Report on memory used by the kernel zone allocator, by zone. 201The information shown is the same as that returned by the 202.Va vm.zone 203sysctl variable. 204.El 205.Pp 206By default, 207.Nm 208displays the following information: 209.Pp 210.Bl -tag -width indent 211.It procs 212Information about the numbers of processes in various states. 213.Pp 214.Bl -tag -width indent -compact 215.It r 216in run queue 217.It b 218blocked for resources (i/o, paging, etc.) 219.It w 220runnable or short sleeper (< 20 secs) but swapped 221.El 222.It memory 223Information about the usage of virtual and real memory. 224Virtual pages (reported in units of 1024 bytes) are considered active if 225they belong to processes which are running or have run in the last 20 226seconds. 227.Pp 228.Bl -tag -width indent -compact 229.It avm 230active virtual pages 231.It fre 232size of the free list 233.El 234.It page 235Information about page faults and paging activity. 236These are averaged each five seconds, and given in units per second. 237.Pp 238.Bl -tag -width indent -compact 239.It flt 240total number of page faults 241.It re 242page reclaims (simulating reference bits) 243.\" .It at 244.\" pages attached (found in free list) 245.It pi 246pages paged in 247.It po 248pages paged out 249.It fr 250pages freed per second 251.\" .It de 252.\" anticipated short term memory shortfall 253.It sr 254pages scanned by clock algorithm, per-second 255.El 256.It disks 257Disk operations per second (this field is system dependent). 258Typically paging will be split across the available drives. 259The header of the field is the first two characters of the disk name and 260the unit number. 261If more than three disk drives are configured in the system, 262.Nm 263displays only the first three drives, unless the user specifies the 264.Fl n 265argument to increase the number of drives displayed. This will probably 266cause the display to exceed 80 columns, however. 267To force 268.Nm 269to display specific drives, their names may be supplied on the command line. 270The 271.Nm 272utility 273defaults to show disks first, and then various other random devices in the 274system to add up to three devices, if there are that many devices in the 275system. If devices are specified on the command line, or if a device type 276matching pattern is specified (see above), 277.Nm 278will only display the given devices or the devices matching the pattern, 279and will not randomly select other devices in the system. 280.It faults 281Trap/interrupt rate averages per second over last 5 seconds. 282.Pp 283.Bl -tag -width indent -compact 284.It in 285device interrupts per interval (including clock interrupts) 286.It sy 287system calls per interval 288.It cs 289cpu context switch rate (switches/interval) 290.El 291.It cpu 292Breakdown of percentage usage of CPU time. 293.Pp 294.Bl -tag -width indent -compact 295.It us 296user time for normal and low priority processes 297.It sy 298system time 299.It id 300cpu idle 301.El 302.El 303.Sh EXAMPLES 304The command: 305.Dl vmstat -w 5 306will print what the system is doing every five 307seconds; this is a good choice of printing interval since this is how often 308some of the statistics are sampled in the system. 309Others vary every second and running the output for a while will make it 310apparent which are recomputed every second. 311.Pp 312The command: 313.Dl vmstat -p da -p cd -w 1 314will tell vmstat to select the first three direct access or CDROM devices 315and display statistics on those devices, as well as other systems 316statistics every second. 317.Sh FILES 318.Bl -tag -width /boot/kernel/kernel -compact 319.It Pa /boot/kernel/kernel 320default kernel namelist 321.It Pa /dev/kmem 322default memory file 323.El 324.Sh SEE ALSO 325.Xr fstat 1 , 326.Xr netstat 1 , 327.Xr nfsstat 1 , 328.Xr ps 1 , 329.Xr systat 1 , 330.Xr iostat 8 , 331.Xr pstat 8 , 332.Xr sysctl 8 333.Pp 334The sections starting with ``Interpreting system activity'' in 335.%T "Installing and Operating 4.3BSD" . 336.Sh BUGS 337The 338.Fl c 339and 340.Fl w 341options are only available with the default output. 342