[CentOS] swap being used?
lists at spuddy.org
Sat Nov 1 16:15:02 UTC 2008
> I have a machine with 64GB of memory in our lab. We have memory
> demanding processes and natually swap gets used. However when these
> processes are gone and the system is idle, we still see swap being
> used. Is this normal behavior?
Perfectly normal. If the pages that have been swapped out are not used
then the system won't bother paging them back in again; keeps even more
memory free for other uses.
For example, my small 360Mb machine:
total used free shared buffers cached
Mem: 368844 330740 38104 0 14928 248348
-/+ buffers/cache: 67464 301380
Swap: 263160 560 262600
560K of swap in use even though there's 300Mb of free space; that 560K
is just not in active use, so is better off on disk than in RAM.
If you _really_ cared you could swapoff to force the pages back to RAM
and then swapon again. But it's not worth it.
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