topic Re: Kernel Corruption in Operating System - HP-UX

Kernel Corruption

sandeepbodkhe_1 — Wed, 14 Oct 2009 13:12:31 GMT

Hi,

Recently one of my RP7400 system after reboot (uptime =532 days ) hung on the BCH and . after lots of workaround, it was concluded that kernel was corrupt. and we rebuilded system from Ignite recovery.This supports the statement of kernel corruption or /stand filesystem inconsistancy.Now i have to
face the problem management and have to mention the corrective action towards this.
what are the suggestions can be given to check such kernel or /stand health ?
I think fsck wont help since / and /stand filesystems are always mounted.

any suggestion please.

Re: Kernel Corruption

SUDHAKAR_18 — Wed, 14 Oct 2009 13:31:55 GMT

take the backup of the kernel (/stand/vmunix & /stand/system) before performing any activity.

If any thing happens to your kernel, then you can boot through alternate kernel

Re: Kernel Corruption

Steven E. Protter — Wed, 14 Oct 2009 14:13:36 GMT

Shalom,

hpux -is
# from the ISL prompt at console

Thake a look at the size and stamps on the vmunix files

boot the system off a previous kernel,

hpux /stand/vmunix.prev

Then build a new kernel.

This kind of corruption does not often happen. If files are missing from /stand you may need to restore them from an Ignite backup.

SEP

Re: Kernel Corruption

sandeepbodkhe_1 — Wed, 14 Oct 2009 14:26:08 GMT

We prepare make_tape_recovery and it completed successfully for last three times with same corrupt image.When we were trying to boot from that, system was getting panic.
So we used fourth old tape.
I think make_recovery did not really check the file integrety.instead it just backs it up.

Re: Kernel Corruption

Michael Steele_2 — Wed, 14 Oct 2009 15:10:47 GMT

Well of course. vmunix is a compiled binary similar to any other 'c' a.out file. And checking is performed at the time of compilation.

Re: Kernel Corruption

Horia Chirculescu — Thu, 15 Oct 2009 07:56:19 GMT

"I think make_recovery did not really check the file integrety.instead it just backs it up."

File integrity is usually handled by CRC checksums embeded in the storege. If there is a problem, you'll find out when the tape drive would actually save the data on tape.

If you have completed archive jobs without any errors, suggests that somehow afther saving the data on media, the media itself is corrupted.

Best regards from Romania,
Horia Chirculescu.