interleaved swapping

[Troyan Krastev]

Hi all,

I created a secondary swap volume on different physical
drive with same priority like the primary swap volume:
------------------------------------------------------
# swapinfo -at
Kb Kb Kb PCT START/ Kb
TYPE AVAIL USED FREE USED LIMIT RESERVE PRI NAME
dev 1703936 155368 1548568 9% 0 - 1 /dev/vg00/lvol2
dev 1703936 52164 1651772 3% 0 - 1 /dev/vg00/swap
reserve - 969756 -969756
total 3407872 1177288 2230584 35% - 0 -
------------------------------------------------------
Why is the percentage usage different? I expected
"interleaved swapping" and equal numbers under
"PCT USED" column!

Troy.

[A. Clay Stephenson · Accepted solution]

Hi Troyan,

The interleaving is working correctly; otherwise, you would see all of one swap area used before any of the next priority is touched. What is confusing you is that the usage is not equal. You have to ask yourself, how likely is it that running processes will need to page_out on such an equal basis.

Clay