vmstat(1M) vmstat(1M)
NAME
vmstat - report virtual memory statistics
SYNOPSIS
/usr/ucb/vmstat [-d|-S] [interval [count]]
/usr/ucb/vmstat -f -m -s
DESCRIPTION
vmstat examines the system and normally reports certain statistics
kept about process, virtual memory, disk, trap and cpu activity.
OPTIONS
No option specified:
vmstat reports (in the fist line) a summary of the virtual memory
activity since the system has booted.
-d Reports the disk assignments (e.g. d0 = ios0/sdisk000,
d1 = ios0/sdisk010 etc.).
-S Prints the "si" and "so" format fields, instead of the "re" and
"at" format fields (see below).
-f Reports on the number of forks since system startup.
-m Reports on the number of physical pages currently being used by
the operating system.
-s Prints the contents of the sum structure, giving the total number
of several kinds of paging-related events which have occurred
since boot.
interval
If interval is specified, then successive lines (after the first)
are summaries over the last interval seconds.
vmstat 5 will print what the system is doing every five seconds;
a print interval of 5 seconds is recommended as statistics are
tested in the system every 5 seconds. Other statistics vary every
second; running the output for a while will make it apparent
which statistics are recomputed every second.
count
If a count is given, the statistics are repeated count times.
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vmstat(1M) vmstat(1M)
Format fields
procs Information about numbers of processes in various states.
r In run queue.
b Blocked for resources (I/O, paging, etc.).
w Operable process or short sleeper (< 20 secs) but
swapped.
memory Information about the usage of virtual and real memory. Vir-
tual 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.
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 second.
re Page reclaims.
si Swap ins (when called with the -S option).
at Pages attached (found in free list).
so Swap outs (when called with the -S option).
pi Pages paged in.
po Pages paged out.
fr Pages freed per second.
sr Pages scanned by clock algorithm, per second.
cpu(s) Breakdown of percentage usage of CPU time as well as the
number of interrupts, system calls and context switches per
second.
in Device interrupts fielded by this cpu per second.
syc System calls per second.
cs Number of context switches per second.
us Percentage of cpu time spent in user mode.
sy Percentage of cpu time spent in system mode (other than
idle).
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vmstat(1M) vmstat(1M)
id Percentage of cpu time spent in idle or I/O wait mode.
io Percentage of cpu time spent in I/O wait mode.
The following line(s) contains/contain I/O statistics for individual
controllers as well as global I/O statistics.
EXAMPLES
Calls (without output):
vmstat
vmstat -d
vmstat -S 5 3
vmstat 5 10
vmstat -fs
Calls (with output):
vmstat
procs memory page cpu(s)
r b w avm fre re at pi po fr sr in syc cs us sy id io
2 0 0 8484 304860 0 32 0 1 1 0 18 161 22 1 11 81 7
0s00: 2 0s03: 2 0s04: 1 0s05: 0 0s06: 2 Total: 6
SEE ALSO
scstat(8).
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