VMSTAT(1) UNIX Programmer's Manual VMSTAT(1)
vmstat - report virtual memory statistics
S
\bSY
\bYN
\bNO
\bOP
\bPS
\bSI
\bIS
\bS
v
\bvm
\bms
\bst
\bta
\bat
\bt [ -
\b-f
\bfs
\bsi
\bim
\bm ] [ drives ] [ interval [ count ] ]
D
\bDE
\bES
\bSC
\bCR
\bRI
\bIP
\bPT
\bTI
\bIO
\bON
\bN
_
\bV_
\bm_
\bs_
\bt_
\ba_
\bt delves into the system and normally reports certain
statistics kept about process, virtual memory, disk, trap
and cpu activity. If given a -
\b-f
\bf argument, it instead
reports on the number of _
\bf_
\bo_
\br_
\bk_
\bs and _
\bv_
\bf_
\bo_
\br_
\bk_
\bs since system
startup and the number of pages of virtual memory involved
in each kind of fork. If given a -
\b-s
\bs argument, it instead
prints the contents of the _
\bs_
\bu_
\bm structure, giving the total
number of several kinds of paging related events which have
occurred since boot. If given a -
\b-i
\bi argument, it instead
reports on the number of _
\bi_
\bn_
\bt_
\be_
\br_
\br_
\bu_
\bp_
\bt_
\bs taken by each device
since system startup. If given a -
\b-m
\bm argument, it instead
reports on the usage of kernel dynamic memory listed first
by _
\bs_
\bi_
\bz_
\be of allocation and then by _
\bt_
\by_
\bp_
\be of usage.
If none of these options are given, _
\bv_
\bm_
\bs_
\bt_
\ba_
\bt will report in
the first line a summary of the virtual memory activity
since the system has been booted. If _
\bi_
\bn_
\bt_
\be_
\br_
\bv_
\ba_
\bl is specified,
then successive lines are summaries over the last _
\bi_
\bn_
\bt_
\be_
\br_
\bv_
\ba_
\bl
seconds. ``vmstat 5'' will print what the system is doing
every five seconds; this is a good choice of printing inter-
val since this is how often some of the statistics are sam-
pled in the system; others vary every second, running the
output for a while will make it apparent which are recom-
puted every second. If a _
\bc_
\bo_
\bu_
\bn_
\bt is given, the statistics are
repeated _
\bc_
\bo_
\bu_
\bn_
\bt times. The format fields are:
Procs: information about numbers of processes in various
b blocked for resources (i/o, paging, etc.)
w 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.
fre size of the free list
Page: information about page faults and paging activity.
These are averaged each five seconds, and given in units per
Printed 7/9/88 February 27, 1988 1
VMSTAT(1) UNIX Programmer's Manual VMSTAT(1)
re page reclaims (simulating reference bits)
at pages attached (found in free list)
fr pages freed per second
de anticipated short term memory shortfall
sr pages scanned by clock algorithm, per-second
up/hp/rk/ra: Disk operations per second (this field is sys-
tem dependent). Typically paging will be split across
several of the available drives. The number under each of
these is the unit number.
Faults: trap/interrupt rate averages per second over last 5
in (non clock) device interrupts per second
sy system calls per second
cs cpu context switch rate (switches/sec)
Cpu: breakdown of percentage usage of CPU time
us user time for normal and low priority processes
If more than 4 disk drives are configured in the system,
_
\bv_
\bm_
\bs_
\bt_
\ba_
\bt displays only the first 4 drives, with priority given
to Massbus disk drives (i.e. if both Unibus and Massbus
drives are present and the total number of drives exceeds 4,
then some number of Unibus drives will not be displayed in
favor of the Massbus drives). To force _
\bv_
\bm_
\bs_
\bt_
\ba_
\bt to display
specific drives, their names may be supplied on the command
S
\bSE
\bEE
\bE A
\bAL
\bLS
\bSO
\bO
_
\bs_
\by_
\bs_
\bt_
\ba_
\bt(1), _
\bi_
\bo_
\bs_
\bt_
\ba_
\bt(1)
The sections starting with ``Interpreting system activity''
in _
\bI_
\bn_
\bs_
\bt_
\ba_
\bl_
\bl_
\bi_
\bn_
\bg _
\ba_
\bn_
\bd _
\bO_
\bp_
\be_
\br_
\ba_
\bt_
\bi_
\bn_
\bg _
\b4._
\b2_
\bb_
\bs_
\bd.
Printed 7/9/88 February 27, 1988 2
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