unable to increase shmmax

[Sanjiv Sharma_1]

Hi,

I am unable to increase the shmmax value in my HP-UX 11i server.

Presently it is 1,073,741,824. It says it is the maximum value.

But I have some HP-UX 11.00 servers and the shmmax value in those are 4,294,967,296.

Why is it so?

Thanks,
Raje.

[Steve Steel]

Hi

I think

http://forums.itrc.hp.com/cm/QuestionAnswer/1,,0x9c96e7e60861d511abcd0090277a778c,00.html

Is the gospel for this one . Please read


Regards

Steve Steel

Quote of the moment
-------------------
"We are drowning in information but starved for knowledge."
-- John Naisbitt

[Michael Tully]

There is a problem from within 'sam' from doing this. I'm sure that there is a patch for this.

Your best bet is doing it from the command line options from 'kmtune'

# kmtune -s shmmax=4294967296
To update the kernel
# kmtune -u

Consult the man page of 'kmtune' for extra details.

[John Palmer]

11i is correct, 1Gb is the maximum for the size of a single 32bit shared memory segment.

I believe that some versions of 11 had an incorrect setting in sam.

Regards,
John

[Alex Glennie · Accepted solution]

Patch Name: PHKL_24032

Patch Description: s700_800 11.11 Setting proper maximum for 64-bit SHMMAX


Symptoms:
PHKL_24032:
( SR:8606177377 CR:JAGad46609 )
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.

[Ravi_8]

Hi,

#kmtune -s shmmax=
#/stand/build/mk_kernel
#mv /stand/build/vmunix_test /stand/vmunix
#rebbot
#kmtune |grep shmmax

now shmmax will be set to the specified value