vmstat output:

procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu----
 r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa
 1  1      0 1001568  84736 500928    0    0    47    30   36   63  1  0 99  1

free output :

             total       used       free     shared    buffers     cached
Mem:       1918500     916592    1001908          0      84732     500576
-/+ buffers/cache:     331284    1587216
Swap:      1948668          0    1948668

How total memory in vmstat is calculated ?

  • What exactly is your question? The number that appears under the column free in the vmstat command is the same number under free in the free command. Same goes for buffers and cached. – Alaa Ali Aug 28 '14 at 22:24
  • aren't the same concerning memory usage ? – nux Aug 28 '14 at 22:29

From the manpages: free, vmstat

free displays the total amount of free and used physical and swap memory in the system, as well as the buffers used by the kernel. The shared memory column should be ignored; it is obsolete.

vmstat reports information about processes, memory, paging, block IO, traps, and cpu activity.

The first report produced gives averages since the last reboot. Additional reports give information on a sampling period of length delay. The process and memory reports are instantaneous in either case.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.