SAM resets shmmax?

[Ron Levy]

Recently we've had a problem with our Oracle database. Upon tracing it, we seem to be running out of memory. Oracle informed us that our shared memory is too low and that there is a bug wherein SAM silently sets SHMMAX to its default value of 64MB. Indeed, when we check our kernel parameters, it's down at 64MB instead of 1G where it should be.

Is there any additional information about this bug, or is there a patch for it? I've been searching here on ITRC and I haven't found it.

[Helen French]

Hi Ron:

Which OS version ? If it's 11.11 , then there is a patch available - PHKL_24032 (s700_800 11.11 Setting proper maximum for 64-bit SHMMAX). Read the patch description. It says:

"Symptoms: SAM will not allow setting the VM tunable SHMMAX above the 32-bit maximum of 0x40000000 on 64-bit kernels, when the documentation (and design) specifies a 64-bit limit of 0x40000000000. Also, SAM will attempt to lower the value of SHMMAX back to the lower maximum if it has been raised to a higher value by other means"

HTH,
Shiju

[S.K. Chan]

SAM is such a pain sometimes .. can you check this file /usr/conf/master.d/sysv-shm and look for the line that says ..

*range shmmax<=0x40000000

Change the above limit to higher because the above hex value about equals 1GB, so this tweak should enable SAM to extend it's limit beyond 1GB. It should look like ..

*range shmmax<=0x40000000000

# /usr/sam/lbin/getkinfo -b
===> will update SAM config file.

Now you should be fine ..

[Craig Rants]

Only thing I found for 11.x or 10.20 is PHCO_22268, which is a 10.20 patch which addresses and shmmax value error.

HTH,
C

[Helen French]

Hi Ron:

Another document about the same issue (TKB #8606178965):

http://us-support.external.hp.com/cki/bin/doc.pl/sid=ba85880214402045bd/screen=ckiDisplayDocument?docId=200000055176255

HTH,
Shiju