vmstat output explained

Table 11-4 Output From the vmstat Command

Category
Field Name
Description
procs
Reports on the following:
r
The number of kernel threads in the dispatch queue
b
The number of blocked kernel threads that are waiting for resources
w
The number of swapped out LWPs that are waiting for processing resources to finish
memory
Reports on usage of real memory and virtual memory:
swap
Available swap space
free
Size of the free list
page
Reports on page faults and paging activity, in units per second:
re
Pages reclaimed
mf
Minor faults and major faults
pi
Kbytes paged in
po
Kbytes paged out
fr
Kbytes freed
de
Anticipated memory that is needed by recently swapped-in processes
sr
Pages scanned by the page daemon not currently in use. If sr does not equal zero, the page daemon has been running.
disk
Reports the number of disk operations per second, showing data on up to four disks
faults
Reports the trap/interrupt rates per second:
in
Interrupts per second
sy
System calls per second
cs
CPU context switch rate
cpu
Reports on the use of CPU time:
us
User time
sy
System time
id
Idle time

For a more detailed description of this command, see the vmstat(1M) man page.

How to Display Virtual Memory Statistics (vmstat)

  • Collect virtual memory statistics by using the vmstat command with a time interval in seconds.
    $ vmstat n

    where n is the interval in seconds between reports.

Example 11-1 Displaying Virtual Memory Statistics

The following example shows the vmstat display of statistics that were gathered at five-second intervals:

$ vmstat 5
kthr memory page disk faults cpu
 r b w swap free re mf pi po fr de sr dd f0 s1 -- in sy cs us sy id
 0 0 0 863160 365680 0 3 1 0 0 0 0 0 0 0 0 406 378 209 1 0 99
 0 0 0 765640 208568 0 36 0 0 0 0 0 0 0 0 0 479 4445 1378 3 3 94
 0 0 0 765640 208568 0 0 0 0 0 0 0 0 0 0 0 423 214 235 0 0 100
 0 0 0 765712 208640 0 0 0 0 0 0 0 3 0 0 0 412 158 181 0 0 100
 0 0 0 765832 208760 0 0 0 0 0 0 0 0 0 0 0 402 157 179 0 0 100
 0 0 0 765832 208760 0 0 0 0 0 0 0 0 0 0 0 403 153 182 0 0 100
 0 0 0 765832 208760 0 0 0 0 0 0 0 0 0 0 0 402 168 177 0 0 100
 0 0 0 765832 208760 0 0 0 0 0 0 0 0 0 0 0 402 153 178 0 0 100
 0 0 0 765832 208760 0 18 0 0 0 0 0 0 0 0 0 407 165 186 0 0 100

How to Display System Event Information (vmstat -s)

  • Run the vmstat -s command to show how many system events have taken place since the last time the system was booted.
    $ vmstat -s
     0 swap ins
     0 swap outs
     0 pages swapped in
     0 pages swapped out
     522586 total address trans. faults taken
     17006 page ins
     25 page outs
     23361 pages paged in
     28 pages paged out
     45594 total reclaims
     45592 reclaims from free list
     0 micro (hat) faults
     522586 minor (as) faults
     16189 major faults
     98241 copy-on-write faults
     137280 zero fill page faults
     45052 pages examined by the clock daemon
     0 revolutions of the clock hand
     26 pages freed by the clock daemon
     2857 forks
     78 vforks
     1647 execs
     34673885 cpu context switches
     65943468 device interrupts
     711250 traps
     63957605 system calls
     3523925 total name lookups (cache hits 99%)
     92590 user cpu
     65952 system cpu
     16085832 idle cpu
     7450 wait cpu

How to Display Swapping Statistics (vmstat -S)

  • Run vmstat -S to show swapping statistics.
    $ vmstat -S
    kthr memory page disk faults cpu
     r b w swap free si so pi po fr de sr dd f0 s1 -- in sy cs us sy id
     0 0 0 862608 364792 0 0 1 0 0 0 0 0 0 0 0 406 394 213 1 0 99

    The swapping statistics fields are described in the following list. For a description of the other fields, see Table 11-4.

    si
    Average number of LWPs that are swapped in per second
    so
    Number of whole processes that are swapped out