paging space kill

[snef]

Hi,
It seems that on AIX 4.3.3 you don't get a paging space kill when running low on virtual memory.
This even has caused my AIX to hang !

Anybody knows if this is normal.


Snef

 

[Yegolev]

I do know that if you run out of memory, your box will hang. I'd call it normal.

 

[snef]

Yes but under AIX 4.2.1 the AIX would kill some processes, freeing memory for itself so it wouldn't hang.

 

[gheist]

root never gets killed ( you can adjust it by /usr/samples/kernel/vmtune ) and system surely hangs if there is not enough memory to run processes owned by root
System will run out of memory more often if you dont have at least 2xRAM sized paging space (or at least 1G) (-:

 

[avadh]

Hello,
in vmtune there is setting that you can setup to kill process once you reach limit.
What application are you running.

 

[snef]

Application that was using up memory wasn't owned by root (cause was the memory leak in libc)
If I read your answers correct than the default behaviour doesn't send paging space kills to non-root processes but you can change it with vmtune, and root processes are never subject to paging space kills.

FYI: System had over 3 gig paging space.


Snef

 

[gheist]

no - it sends paging kills to users whose id is below value specified with vmtune -n <##> at the reasonable rate ( ie not complete kill at a time)

 

[gheist]

sorry

-below
+above

 

[avadh]

Hello,
Go to

http://www.redbooks.ibm.com

find redbook on performance then look at section on vmtune it explain in detail.