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 imsuvz 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 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 u 177Output unformatted numeric values, suitable for field extraction and 178numeric sorting. 179Columnar output will not be nicely aligned. 180.It Fl v 181If specified together with 182.Fl i , 183include IRQ numbers and IRQ target CPU numbers before device names. 184.It Fl w 185Pause 186.Ar wait 187seconds between each display. 188If no repeat 189.Ar wait 190interval is specified, the default is 1 second. 191.It Fl z 192Report on memory used by the kernel zone allocator, by zone. 193The information shown is the same as that returned by the 194.Va vm.zone 195sysctl variable. 196.El 197.Pp 198By default, 199.Nm 200displays the following information: 201.Bl -tag -width indent 202.It procs 203Information about the numbers of processes in various states. 204.Pp 205.Bl -tag -width indent -compact 206.It r 207in run queue 208.It b 209blocked for resources (i/o, paging, etc.) 210.It w 211runnable or short sleeper (< 20 secs) but swapped 212.El 213.It memory 214Information about the usage of virtual and real memory. 215Virtual pages (reported in units of 1024 bytes) are considered active if 216they belong to processes which are running or have run in the last 20 217seconds. 218.Pp 219.Bl -tag -width indent -compact 220.It fre 221Approximate free and easily-freeable memory. 222.El 223.It page 224Information about page faults and paging activity. 225These are averaged each five seconds, and given in units per second. 226.Pp 227.Bl -tag -width indent -compact 228.It flt 229total number of page faults 230.It re 231page reclaims (simulating reference bits) 232.\" .It at 233.\" pages attached (found in free list) 234.It pi 235pages paged in 236.It po 237pages paged out 238.It fr 239pages freed per second 240.\" .It de 241.\" anticipated short term memory shortfall 242.El 243.It disks 244Disk operations per second (this field is system dependent). 245Typically paging will be split across the available drives. 246The header of the field is the first two characters of the disk name and 247the unit number. 248If more than three disk drives are configured in the system, 249.Nm 250displays only the first three drives, unless the user specifies the 251.Fl n 252argument to increase the number of drives displayed. This will probably 253cause the display to exceed 80 columns, however. 254To force 255.Nm 256to display specific drives, their names may be supplied on the command line. 257.Nm 258defaults to show disks first, and then various other random devices in the 259system to add up to three devices, if there are that many devices in the 260system. If devices are specified on the command line, or if a device type 261matching pattern is specified (see above), 262.Nm 263will only display the given devices or the devices matching the pattern, 264and will not randomly select other devices in the system. 265.It faults 266Trap/interrupt rate averages per second over last 5 seconds. 267.Pp 268.Bl -tag -width indent -compact 269.It int 270device interrupts per interval (including clock interrupts) 271.It sys 272system calls per interval 273.It ctx 274cpu context switch rate (switches/interval) 275.El 276.It cpu 277Breakdown of percentage usage of CPU time. 278.Pp 279.Bl -tag -width indent -compact 280.It us 281user time for normal and low priority processes 282.It sy 283system time 284.It id 285cpu idle 286.El 287.El 288.Sh FILES 289.Bl -tag -width /dev/kmemxxx -compact 290.It Pa /boot/kernel 291default kernel namelist 292.It Pa /dev/kmem 293default memory file 294.El 295.Sh EXAMPLES 296The command: 297.Dl vmstat -w 5 298will print what the system is doing every five 299seconds; this is a good choice of printing interval since this is how often 300some of the statistics are sampled in the system. 301Others vary every second and running the output for a while will make it 302apparent which are recomputed every second. 303.Pp 304The command: 305.Dl vmstat -p da -p cd -w 1 306will tell vmstat to select the first three direct access or CDROM devices 307and display statistics on those devices, as well as other systems 308statistics every second. 309.Sh SEE ALSO 310.Xr fstat 1 , 311.Xr netstat 1 , 312.Xr nfsstat 1 , 313.Xr ps 1 , 314.Xr systat 1 , 315.Xr iostat 8 , 316.Xr pstat 8 , 317.Xr sysctl 8 318.Pp 319The sections starting with ``Interpreting system activity'' in 320.%T "Installing and Operating 4.3BSD" . 321.Sh BUGS 322The 323.Fl c 324and 325.Fl w 326options are only available with the default output. 327