Kernel changes not appearing in /stand/system or sysdef

[Kevin Urschatz]

System: HP-UX 11.0 L-Class server

We had a kernel change to maxtsiz.
When I look at the value in SAM it exists.
When I grep on /stand/system it is not listed.
As well when I run sysdef it's not listed.

I need to know why? Any ideas?

[Denver Osborn]

When you made the changes did you allow the system to reboot off the new kernel or when SAM prompted did you choose to move kernel into place at a later time and reboot?

Are the current and pending values the same? If you look in /stand/build is there a system.SAM file?

[Tony Constantine_1]

This is the way you should build a kernel on HPUX11

cd /stand/build

/usr/lbin/sysadm/system_prep -s system

edit /stand/build/system and change required kernel params

/usr/sbin/mk_kernel -s /stand/build/system

backup old kernel and systems files

mv /stand/system /stand/system.prev
mv /stand/vmunix /stand/vmunix.prev

Install new kernel

cp /stand/build/system /stand
cp /stand/build/vmunix_test /stand/vmunix

Reboot server

shutdoen -r 0

[Kevin Urschatz]

The current and pending values are the same.
We did not choose the option to move the kernel into place and reboot at a later time.

It booted with the new value in place.

We've done the same procedure on many occassions without running into this problem.

Basically do I trust the values reported in SAM, sysdef or /stand/system?

[Victor BERRIDGE]

There is nothing wrong using sam to alter kernel parameters and generate a new kernel, in fact you are playing safe doing it this way when you are modifying the tunable params, but as Denver mentionned, atfer building a new kernel, SAM asks you if you want to reboot NOW... or move the kernel into place at a later time...
If the second alternative has been chosen, I remember SAM saying YOU have to move /stand/build/system.SAM to /stand/system...

[Victor BERRIDGE]

Are the timestamps of /stand/system and/stand/vmunix the same?

[James R. Ferguson]

Kevin:

As regards maxtsiz, SAM reports it in bytes while sysdev reports it in page units. Multiply the value you see in sysdev by 4096 and see if you get what you expect(ed).

As for manually generating the Kernel by editing /stand/system -- I wouldn't do that unless SAM had a bug (which I've seen). SAM has the rulesets for the correct interrelationships among the various kernel parameters and will not let you build an unbootable one. By allowing SAM to guide you through setting kernel parameters you end up with an optimal kernel, too.

...JRF...

[Wade Satterfield · Accepted solution]

Looking at /stand/system for kernel parameters is rarely complete. If a parameter is set to its default value it will not appear in /stand/system. This could be your problem.

SAM and kmtune give a more or less complete view of the kernel parameters that will be used in the next kernel build because they fill in any missing values with the default value.

If your new value for maxtsiz happens to be
the same as the default value, both SAM and kmtune will delete it from /stand/system. This may explain why you don't see it with grep.