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VMSTAT(8)		FreeBSD	System Manager's Manual		     VMSTAT(8)

NAME
     vmstat -- report statistics about kernel activities

SYNOPSIS
     vmstat [-fimstvz]
     vmstat [-c	count] [-M core] [-N system] [-w wait] [disk ...]

DESCRIPTION
     vmstat reports certain kernel statistics kept about process, virtual mem-
     ory, disk,	trap, and CPU activity.	 The default behavior is to print a
     one-line summary of these statistics.  The	-c and -w flags	may be used to
     continually report	summaries.

     The options are as	follows:

     -c	count
	     Repeat the	display	count times.  The first	display	is for the
	     time since	a reboot and each subsequent report is for the time
	     period since the last display.  If	no wait	interval is specified,
	     the default is 1 second.

     -f	     Report on the number of fork(2), __tfork(3), and vfork(2) system
	     calls as well as kernel thread creations since system startup,
	     and the number of pages of	virtual	memory involved	in each.

     -i	     Report on the number of interrupts	taken by each device since
	     system startup.

     -M	core
	     Extract values associated with the	name list from the specified
	     core instead of the running kernel.

     -m	     Report on the usage of kernel dynamic memory listed first by size
	     of	allocation and then by type of usage.

     -N	system
	     Extract the name list from	the specified system instead of	the
	     running kernel.

     -s	     Display the contents of the uvmexp	structure (see uvm_init(9)),
	     giving the	total number of	several	kinds of paging	related	events
	     which have	occurred since system startup.

     -t	     Report on the number of page in and page reclaims since system
	     startup, and the amount of	time required by each.

     -v	     Print more	verbose	information.

     -w	wait
	     Pause wait	seconds	between	each display.  If no repeat count is
	     specified,	the default is infinity.

     -z	     When used with -i,	also list devices which	have not yet generated
	     an	interrupt.

     By	default, vmstat	displays the following information just	once:

     procs   Information about the numbers of processes	in various states.

	     r	   in run queue
	     s	   sleeping

     memory  Information about the usage of virtual and	real memory.

	     avm   active virtual pages
	     fre   size	of the free list

     page    Information about page faults and paging activity.	 These are av-
	     eraged each five seconds, and given in units per second.

	     flt   page	faults
	     re	   page	reclaims (simulating reference bits)
	     pi	   pages paged in
	     po	   pages paged out
	     fr	   pages freed
	     sr	   pages scanned by clock algorithm

     disks   Disk transfers per	second.	 Typically paging will be split	across
	     the available drives.  The	header of the field is the first char-
	     acter of the disk name and	the unit number.  If more than two
	     disk drives are configured	in the system, vmstat displays only
	     the first two drives.  To force vmstat to display specific
	     drives, their names may be	supplied on the	command	line.

     traps   Trap/interrupt rate averages per second over last 5 seconds.

	     int   device interrupts per interval (including clock interrupts)
	     sys   system calls	per interval
	     cs	   CPU context switch rate (switches/interval)

     cpu     Breakdown of percentage usage of CPU time.

	     us	   user	time for normal	and low	priority processes
	     sy	   system time
	     id	   CPU idle

FILES
     /bsd			       default kernel image
     /dev/kmem			       default memory file

EXAMPLES
     The command vmstat	-w 5 will print	what the system	is doing every five
     seconds; this is a	good choice of printing	interval since this is how of-
     ten some of the statistics	are sampled in the system.  Others vary	every
     second and	running	the output for a while will make it apparent which are
     recomputed	every second.

SEE ALSO
     fstat(1), netstat(1), nfsstat(1), procmap(1), ps(1), systat(1), top(1),
     iostat(8),	pstat(8), uvm_init(9)

BUGS
     The -c and	-w options are only available with the default output.

     This manual page lacks an incredible amount of detail.

FreeBSD	13.0		       December	6, 2019			  FreeBSD 13.0

NAME | SYNOPSIS | DESCRIPTION | FILES | EXAMPLES | SEE ALSO | BUGS

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