kernel virtual memory limit

[Rainer von Bongartz]

I encountered the following syslog messages

Apr 22 14:48:33 venus vmunix: System is close to kernel virtual memory limit (KVMLIMIT).
Apr 22 14:48:33 venus vmunix: This is an abnormal condition and the kernel will attempt to
Apr 22 14:48:33 venus vmunix: reclaim some space. Please check the tunable parameters.


Which tunable parameters do I have to check ???

kmtune does not report a parameter named KVMLIMIT

Regards
Rainer

[Paula J Frazer-Campbell]

Hi

KVMLIMIT is NOT a tunable limit.

It could be a kenel tunable, but most likly is a program with a memory leak.

Fire uo

Top
Glance
Sar
swapinfo

and check what is using the memory.


Paula

[Paula J Frazer-Campbell]

Hi

Fire uo

Should be


Fire up.


Paula

[harry d brown jr]

Rainer,

Can you post your kernel parameters and swapinfo?

live free or die
harry

[Bill McNAMARA_1]

sysdef
will give you acceptable limits and the current settings.

swapinfo -tm for guess what!,

Later,
bill

[Rainer von Bongartz]

In The meantime a had a panic on my box with:

Apr 22 15:19:46 venus vmunix: panic: kalloc: out of kernel virtual space

harry, attached you'll find kmtune and swapinfo listings

Regards
Rainer

Mb Mb Mb PCT START/ Mb
TYPE AVAIL USED FREE USED LIMIT RESERVE PRI NAME
dev 1024 0 1024 0% 0 - 1 /dev/vg00/lvol2
reserve - 527 -527
memory 940 220 720 23%
total 1964 747 1217 38% - 0 -

[Helen French]

Hi Rainer:

Did you check the 'maxswapchunks' value ? You can check the virtual memroy status with glance and find out what will be the exact problem.

HTH,
Shiju

[hpuxrox]

try

ipcs -m

Take a look around there.

[Ruediger Noack]

Hi,

how Paula said look at your processes because of memory usage. You can get the top virtual memory usage processes like this:
UNIX95= ps -e -o ruser,sz,vsz,pid,args | sort -rnk3 | head -3

May be like on my box a few weeks ago you have got a memory leak with mib2agt. In this case stop and start the agent to get back the wasted memory and install the patch (PHSS_24945).

[Helen French]

Hi Rainer:

There can be different reasons for the reboot after panic:

1) Check the syslog.log file and if you have sysmap overflows, then increase the kernel parameter - nproc. This will ultimately increase some other parameters too.

2) Apply the latest patch bundle from HP site. Some of the kernel patches has fix for this type of errors.

3) Monitor the system usage and resorces with glance.

4) Check for any hardware and HPMC errors

HTH,
Shiju