kernal parameters dissapear or revert to default after reboot or patching.

[Daniel Simard]

Good afternoon All,
Here is my question. I patched 2 unix servers. (L classes with 11.11 march 2003 bundle) on a Friday at 6pm. Everything went well (no errors at all.) The next day, we get a call from one of our DBA's saying that they get an error message (something about FORK: Too many processes running etc...) The solution was to increase the maxuprc parameter to 2235 (from 75). The problem is that it was already set to 2235 (before the patching.)

Question: Why would the kernel revert back to default after patching or a little after ?

Have any of you seen this type of problem before? Where a change in the system has changed kernel parameters automatically ?

Any help is appreciated.

[Steven E. Protter · Accepted solution]

kmtune

Check that the system files are not corrupt or missing in /stand

Is there adequate space in /stand ?

Are there a lot of old versions of the system file.

what /stand/vmunix

Is your revised kernel in production, all nice and patched up?

I will assume you checked kmtune prior to the install and all was well.

SEP

[Sridhar Bhaskarla]

Hi,

It is a good practice to keep /stand/system up to date with your kernel though in many instances it is not used as it is. Particularly if you used SAM and didn't chose to overwrite the existing system file might have caused this.

-Sri

[A. Clay Stephenson]

I suspect what happened was that maxuprc was set using kmtune -u to update the running kernel and a different system file was specified or a kmtune -r was used to reset to default value.

This is not normal for a patch although it is possible that if an abnormally high or low value for a parameter were detected, the patch install script might revert to default. Yours is an unusually high value for maxuprc.

[Arockia Jegan]

I had this experience in the past one time. It's with hpux 11i. The patches associated with kernel some times reset the kernel parameter back to the default. I couldn't recollect the patches that caused the problem on my server.

[Caesar_3]

Hello!

Probably when you compiled your kernel
the system file was old or bad so
you get the wrong parameters.

Caesar

[Steven E. Protter]

Now I also recall a few itrc posts that caused this problem. Please list the patches you installed and report the problem to the HP response center.

Whether or not you have a contract, they want to know when this happens.

SEP