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.\" $FreeBSD$ 30.\" 31.Dd May 26, 2020 32.Dt VMSTAT 8 33.Os 34.Sh NAME 35.Nm vmstat 36.Nd report virtual memory statistics 37.Sh SYNOPSIS 38.Nm 39.\" .Op Fl fimst 40.Op Fl -libxo 41.Op Fl afHhimoPsz 42.Op Fl M Ar core Op Fl N Ar system 43.Op Fl c Ar count 44.Op Fl n Ar devs 45.Oo 46.Fl p 47.Sm off 48.Ar type , if , pass 49.Sm on 50.Oc 51.Op Fl w Ar wait 52.Op Ar disks ... 53.Op wait Op count 54.Sh DESCRIPTION 55The 56.Nm 57utility reports certain kernel statistics kept about process, virtual memory, 58disk, trap and cpu activity. 59.Pp 60If the 61.Fl M 62option is not specified, information is obtained from 63the currently running kernel via the 64.Xr sysctl 3 65interface. 66Otherwise, information is read from the specified core file, 67using the name list from the specified kernel image (or from 68the default image). 69.Pp 70The options are as follows: 71.Bl -tag -width indent 72.It Fl -libxo 73Generate output via 74.Xr libxo 3 75in a selection of different human and machine readable formats. 76See 77.Xr xo_parse_args 3 78for details on command line arguments. 79.It Fl a 80When used with 81.Fl i , 82include statistics about interrupts that have never been generated. 83.It Fl c 84Repeat the display 85.Ar count 86times. 87The first display is for the time since a reboot and each subsequent 88report is for the time period since the last display. 89If no repeat 90.Ar count 91is specified, and 92.Fl w 93is specified, the default is infinity, otherwise the default is one. 94.It Fl f 95Report on the number 96.Xr fork 2 , 97.Xr vfork 2 98and 99.Xr rfork 2 100system calls since system startup, and the number of pages of virtual memory 101involved in each. 102.It Fl h 103Changes memory columns into more easily human readable form. 104The default if 105standard output is a terminal device. 106.It Fl H 107Changes memory columns into straight numbers. 108The default if standard output 109is not a terminal device (such as a script). 110.It Fl i 111Report on the number of interrupts taken by each device since system 112startup. 113.It Fl M 114Extract values associated with the name list from the specified 115.Ar core . 116.It Fl N 117If 118.Fl M 119is also specified, 120extract the name list from the specified 121.Ar system 122instead of the default, 123which is the kernel image the system has booted from. 124.It Fl m 125Report on the usage of kernel dynamic memory allocated using 126.Xr malloc 9 127by type. 128.It Fl n 129Change the maximum number of disks to display from the default of 2. 130.It Fl o 131Display a list of virtual memory objects in the system and the resident 132memory used by each object. 133.It Fl P 134Report per-cpu system/user/idle cpu statistics. 135.It Fl p 136Specify which types of devices to display. 137There are three different 138categories of devices: 139.Pp 140.Bl -tag -width indent -compact 141.It device type: 142.Bl -tag -width 9n -compact 143.It da 144Direct Access devices 145.It sa 146Sequential Access devices 147.It printer 148Printers 149.It proc 150Processor devices 151.It worm 152Write Once Read Multiple devices 153.It cd 154CD devices 155.It scanner 156Scanner devices 157.It optical 158Optical Memory devices 159.It changer 160Medium Changer devices 161.It comm 162Communication devices 163.It array 164Storage Array devices 165.It enclosure 166Enclosure Services devices 167.It floppy 168Floppy devices 169.El 170.Pp 171.It interface: 172.Bl -tag -width 9n -compact 173.It IDE 174Integrated Drive Electronics devices 175.It SCSI 176Small Computer System Interface devices 177.It other 178Any other device interface 179.El 180.Pp 181.It passthrough: 182.Bl -tag -width 9n -compact 183.It pass 184Passthrough devices 185.El 186.El 187.Pp 188The user must specify at least one device type, and may specify at most 189one device type from each category. 190Multiple device types in a single 191device type statement must be separated by commas. 192.Pp 193Any number of 194.Fl p 195arguments may be specified on the command line. 196All 197.Fl p 198arguments are ORed together to form a matching expression against which 199all devices in the system are compared. 200Any device that fully matches 201any 202.Fl p 203argument will be included in the 204.Nm 205output, up to two devices, or the maximum number of devices specified 206by the user. 207.It Fl s 208Display the contents of the 209.Em sum 210structure, giving the total number of several kinds of paging related 211events which have occurred since system startup. 212.\" .It Fl t 213.\" Report on the number of page in and page reclaims since system startup, 214.\" and the amount of time required by each. 215.It Fl w 216Pause 217.Ar wait 218seconds between each display. 219If no repeat 220.Ar wait 221interval is specified, the default is 1 second. 222The 223.Nm 224command will accept and honor a non-integer number of seconds. 225.It Fl z 226Report on memory used by the kernel zone allocator, 227.Xr uma 9 , 228by zone. 229.El 230.Pp 231The 232.Ar wait 233and 234.Ar count 235arguments may be given after their respective flags at any point 236on the command line before the 237.Ar disks 238argument(s), or without their flags, as the final argument(s). 239The latter form is accepted for backwards compatibility, but it is 240preferred to use the forms with 241.Fl w 242and 243.Fl c 244to avoid ambiguity. 245.Pp 246By default, 247.Nm 248displays the following information: 249.Bl -tag -width indent 250.It procs 251Information about the number of threads in various states: 252.Pp 253.Bl -tag -width indent -compact 254.It r 255running or in run queue 256.It b 257blocked for resources (i/o, paging, etc.) 258.It w 259swapped out 260.El 261.It memory 262Information about the usage of virtual and real memory. 263.Pp 264Mapped virtual memory is a sum of all of the virtual pages belonging 265to mapped virtual memory objects. 266Note that the entire memory object's size is considered mapped even if 267only a subset of the object's pages are currently mapped. 268This statistic is not related to the active page queue which is used to track 269real memory. 270.Pp 271.Bl -tag -width indent -compact 272.It avm 273mapped virtual memory 274.Po previously called active in 275.Nm 276output 277.Pc 278.It fre 279size of the free list 280.El 281.It page 282Information about page faults and paging activity. 283These are given in units per second. 284.Pp 285.Bl -tag -width indent -compact 286.It flt 287total number of page faults 288.It re 289page reclaims (simulating reference bits) 290.\" .It at 291.\" pages attached (found in free list) 292.It pi 293pages paged in 294.It po 295pages paged out 296.It fr 297pages freed 298.\" .It de 299.\" anticipated short term memory shortfall 300.It sr 301pages scanned by page daemon 302.El 303.It disks 304Disk operations per second (this field is system dependent). 305Typically paging will be split across the available drives. 306The header of the field is the first two characters of the disk name and 307the unit number. 308If more than two disk drives are configured in the system, 309.Nm 310displays only the first two drives, unless the user specifies the 311.Fl n 312argument to increase the number of drives displayed. 313This will probably 314cause the display to exceed 80 columns, however. 315To force 316.Nm 317to display specific drives, their names may be supplied on the command line. 318The 319.Nm 320utility 321defaults to show disks first, and then various other random devices in the 322system to add up to two devices, if there are that many devices in the 323system. 324If devices are specified on the command line, or if a device type 325matching pattern is specified (see above), 326.Nm 327will only display the given devices or the devices matching the pattern, 328and will not randomly select other devices in the system. 329.It faults 330Trap/interrupt rates per second. 331.Pp 332.Bl -tag -width indent -compact 333.It in 334device interrupts (including clock interrupts) 335.It sy 336system calls 337.It cs 338cpu context switches 339.El 340.It cpu 341Breakdown of percentage usage of CPU time. 342.Pp 343.Bl -tag -width indent -compact 344.It us 345user time for normal and low priority processes 346.It sy 347system and interrupt time 348.It id 349cpu idle 350.El 351.El 352.Sh FILES 353.Bl -tag -width /boot/kernel/kernel -compact 354.It Pa /boot/kernel/kernel 355default kernel namelist 356.It Pa /dev/kmem 357default memory file 358.El 359.Sh EXAMPLES 360The command: 361.Dl vmstat -w 5 362will print what the system is doing every five 363seconds. 364.Pp 365The command: 366.Dl vmstat -p da -p cd -w 1 367will tell vmstat to select the first two direct access or CDROM devices 368and display statistics on those devices, as well as other systems 369statistics every second. 370.Sh SEE ALSO 371.Xr fstat 1 , 372.Xr netstat 1 , 373.Xr nfsstat 1 , 374.Xr ps 1 , 375.Xr systat 1 , 376.Xr libmemstat 3 , 377.Xr libxo 3 , 378.Xr xo_parse_args 3 , 379.Xr gstat 8 , 380.Xr iostat 8 , 381.Xr pstat 8 , 382.Xr sysctl 8 , 383.Xr malloc 9 , 384.Xr uma 9 385.Pp 386The sections starting with ``Interpreting system activity'' in 387.%T "Installing and Operating 4.3BSD" . 388.Sh HISTORY 389The 390.Nm 391utility first appeared in 392.Bx 4.3 . 393.Sh BUGS 394The 395.Fl c 396and 397.Fl w 398options are only available with the default output. 399