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 April 14, 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 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 58The 59.Nm 60utility reports 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 a 66When used with 67.Fl i , 68include statistics about interrupts that have never been generated. 69.It Fl c 70Repeat the display 71.Ar count 72times. 73The first display is for the time since a reboot and each subsequent 74report is for the time period since the last display. 75If no repeat 76.Ar count 77is specified, and 78.Fl w 79is specified, the default is infinity, otherwise the default is one. 80.It Fl f 81Report on the number 82.Xr fork 2 , 83.Xr vfork 2 84and 85.Xr rfork 2 86system calls since system startup, and the number of pages of virtual memory 87involved in each. 88.It Fl i 89Report on the number of interrupts taken by each device since system 90startup. 91.It Fl M 92Extract values associated with the name list from the specified 93.Ar core 94instead of the default 95.Pa /dev/kmem . 96.It Fl N 97Extract the name list from the specified 98.Ar system 99instead of the default 100.Pa /boot/kernel/kernel . 101.It Fl m 102Report on the usage of kernel dynamic memory listed first by size of 103allocation and then by type of usage. 104.It Fl n 105Change the maximum number of disks to display from the default of 2. 106.It Fl p 107Specify which types of devices to display. There are three different 108categories of devices: 109.Pp 110.Bl -tag -width indent -compact 111.It device type: 112.Bl -tag -width 9n -compact 113.It da 114Direct Access devices 115.It sa 116Sequential Access devices 117.It printer 118Printers 119.It proc 120Processor devices 121.It worm 122Write Once Read Multiple devices 123.It cd 124CD devices 125.It scanner 126Scanner devices 127.It optical 128Optical Memory devices 129.It changer 130Medium Changer devices 131.It comm 132Communication devices 133.It array 134Storage Array devices 135.It enclosure 136Enclosure Services devices 137.It floppy 138Floppy devices 139.El 140.Pp 141.It interface: 142.Bl -tag -width 9n -compact 143.It IDE 144Integrated Drive Electronics devices 145.It SCSI 146Small Computer System Interface devices 147.It other 148Any other device interface 149.El 150.Pp 151.It passthrough: 152.Bl -tag -width 9n -compact 153.It pass 154Passthrough devices 155.El 156.El 157.Pp 158The user must specify at least one device type, and may specify at most 159one device type from each category. Multiple device types in a single 160device type statement must be separated by commas. 161.Pp 162Any number of 163.Fl p 164arguments may be specified on the command line. All 165.Fl p 166arguments are ORed together to form a matching expression against which 167all devices in the system are compared. Any device that fully matches 168any 169.Fl p 170argument will be included in the 171.Nm 172output, up to three devices, or the maximum number of devices specified 173by the user. 174.It Fl s 175Display the contents of the 176.Em sum 177structure, giving the total number of several kinds of paging related 178events which have occurred since system startup. 179.\" .It Fl t 180.\" Report on the number of page in and page reclaims since system startup, 181.\" and the amount of time required by each. 182.It Fl w 183Pause 184.Ar wait 185seconds between each display. 186If no repeat 187.Ar wait 188interval is specified, the default is 1 second. 189.It Fl z 190Report on memory used by the kernel zone allocator, by zone. 191The information shown is the same as that returned by the 192.Va vm.zone 193sysctl variable. 194.El 195.Pp 196By default, 197.Nm 198displays the following information: 199.Pp 200.Bl -tag -width indent 201.It procs 202Information about the numbers of processes in various states. 203.Pp 204.Bl -tag -width indent -compact 205.It r 206in run queue 207.It b 208blocked for resources (i/o, paging, etc.) 209.It w 210runnable or short sleeper (< 20 secs) but swapped 211.El 212.It memory 213Information about the usage of virtual and real memory. 214Virtual pages (reported in units of 1024 bytes) are considered active if 215they belong to processes which are running or have run in the last 20 216seconds. 217.Pp 218.Bl -tag -width indent -compact 219.It avm 220active virtual pages 221.It fre 222size of the free list 223.El 224.It page 225Information about page faults and paging activity. 226These are averaged each five seconds, and given in units per second. 227.Pp 228.Bl -tag -width indent -compact 229.It flt 230total number of page faults 231.It re 232page reclaims (simulating reference bits) 233.\" .It at 234.\" pages attached (found in free list) 235.It pi 236pages paged in 237.It po 238pages paged out 239.It fr 240pages freed per second 241.\" .It de 242.\" anticipated short term memory shortfall 243.It sr 244pages scanned by clock algorithm, per-second 245.El 246.It disks 247Disk operations per second (this field is system dependent). 248Typically paging will be split across the available drives. 249The header of the field is the first two characters of the disk name and 250the unit number. 251If more than three disk drives are configured in the system, 252.Nm 253displays only the first three drives, unless the user specifies the 254.Fl n 255argument to increase the number of drives displayed. This will probably 256cause the display to exceed 80 columns, however. 257To force 258.Nm 259to display specific drives, their names may be supplied on the command line. 260The 261.Nm 262utility 263defaults to show disks first, and then various other random devices in the 264system to add up to three devices, if there are that many devices in the 265system. If devices are specified on the command line, or if a device type 266matching pattern is specified (see above), 267.Nm 268will only display the given devices or the devices matching the pattern, 269and will not randomly select other devices in the system. 270.It faults 271Trap/interrupt rate averages per second over last 5 seconds. 272.Pp 273.Bl -tag -width indent -compact 274.It in 275device interrupts per interval (including clock interrupts) 276.It sy 277system calls per interval 278.It cs 279cpu context switch rate (switches/interval) 280.El 281.It cpu 282Breakdown of percentage usage of CPU time. 283.Pp 284.Bl -tag -width indent -compact 285.It us 286user time for normal and low priority processes 287.It sy 288system time 289.It id 290cpu idle 291.El 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 FILES 308.Bl -tag -width /boot/kernel/kernel -compact 309.It Pa /boot/kernel/kernel 310default kernel namelist 311.It Pa /dev/kmem 312default memory file 313.El 314.Sh SEE ALSO 315.Xr fstat 1 , 316.Xr netstat 1 , 317.Xr nfsstat 1 , 318.Xr ps 1 , 319.Xr systat 1 , 320.Xr iostat 8 , 321.Xr pstat 8 , 322.Xr sysctl 8 323.Pp 324The sections starting with ``Interpreting system activity'' in 325.%T "Installing and Operating 4.3BSD" . 326.Sh BUGS 327The 328.Fl c 329and 330.Fl w 331options are only available with the default output. 332