VMSTAT(8)           UNIX Programmer's Manual            VMSTAT(8)

NAME
     vmstat - report system and memory statistics

SYNOPSIS
     vmstat [ -sm ] [ interval [ count ] ]

DESCRIPTION
     _V_m_s_t_a_t delves into the system and normally reports certain
     statistics kept about process, memory and swap, disk, trap
     and cpu activity.  If given a -s argument, it instead prints
     the contents of the _s_u_m structure, giving the total number
     of several kinds of swap and cpu events which have occurred
     since boot.  The -m option causes it to print all of the
     memory usage statistics.  Memory usage is categorized as
     virtual and real, active and inactive (for more than 20
     seconds), text and total, and free memory remaining.  Vir-
     tual memory is the sum of real memory and swap space in use.
     The interval and count options are the same as below.

     If neither option is given, _v_m_s_t_a_t will report in a (usu-
     ally) iterative fashion on the activity in the system.  In
     this case, the optional _i_n_t_e_r_v_a_l argument causes _v_m_s_t_a_t to
     report once each _i_n_t_e_r_v_a_l seconds; ``vmstat 5'' will print
     what the system is doing every five seconds; this is a good
     choice of printing interval since this is how often the
     statistics are sampled in the system.  If a _c_o_u_n_t is given,
     the statistics are repeated _c_o_u_n_t times.  The fields are:

     Procs: information about numbers of processes in various
     states.

     RQ   in run queue
     DW   disk wait
     SW   runnable or short sleeper (< 20 secs) but swapped

     Memory: information about the usage of virtual and real
     memory.  Virtual pages are considered active if they belong
     to processes which are running or have run in the last 20
     seconds.  A ``page'' here is 1024 bytes.

     AVM  active virtual pages
     TX   percent of active pages which are shared text
     FRE  size of the free list

     Swap: information about the swapping activity of the system.

     I    process swap ins in last 5 seconds
     O    process swap outs in last 5 seconds

     Disk: operations per second (this field is system depen-
     dent).

Printed 8/2/83                                                  1

VMSTAT(8)           UNIX Programmer's Manual            VMSTAT(8)

     D0   disk 0
     D1   disk 1
     D2   disk 2
     D3   disk 3

     Faults: trap/interrupt, per second, over last 5 seconds.

     PD   pseudo-DMA interrupts from DZ-11's (per second)
     IN   device interrupts (per second)
     SY   system calls (per second)
     TR   traps (per second)
     OV   overlay traps (per second)
     CS   cpu context switch rate (switches/sec)

     Cpu: breakdown of percentage usage of CPU time

     US   user time for normal processes
     NI   user time for low priority processes
     SY   system time
     ID   cpu idle

FILES
     /dev/kmem
     /unix

BUGS
     This program will only work if the information is maintained
     by the system; some of this is optional and depends on the
     system configuration.

Printed 8/2/83                                                  2