kernel backup

[himacs]

Hi Admin,

I want to boot the server from my backup kernel.

Server is B.11.23

Please tell the exact steps.

Regards,
himacs

[Mel Burslan]

Interrupt the auto boot sequence.

> boot primary
say "y" to interact with ISL question

at ISL prompt, type

ISL> hpux /stand/vmunix.prev

this assumes your old kernel is named vmunix.prev

[himacs]

Hi Mel,,
Thanks for ur reply.Actually i changed some kernel parameters,now required a reboot.

regards
himacs

[Mel Burslan]

so, then, the old kernel is saved with the default name which is vmunix.prev, which makes my suggestion hpux /stand/vmunix.prev a correct assumption. Did you try it ? Did it work ?

[himacs]

Hi,

No i didnot try.I have to get downtime.

regards,
himacs

[UVK]

In 11.23 most of the kernal parameters are Dynamic, I dont mean all.

If you have to reboot using your previous kernal if anything messed up. Break the boot sequence and go to ISL prompt do a

ISL> hpux /stand/vmunix.prev

You will boot from your previous kernal I am assuming that you changed the parameter using SAM or recompiled the kernal using mk_kernal

[Mel Burslan]

good luck with that. Remember to remove the /stand/vmunix and rename vmunix.prev to vmunix, if you are going to stay with the old kernel. Once reboot gets performed, this minor detail gets forgotten until the next reboot and all the hell breaks loose. Just a reminder.

[Md. Minhaz Khan · Accepted solution]

Dear Himacs

After changing your kernel parameter using SAM if new kernel dont work, please follow the below procedure:

Step 1: Booting from the Backup Kernel:
To boot the backup kernel, /stand/vmunix.prev, boot the system manually as described below:

[POWER] #Power-on the system.

[ESC] #Hit the escape key to interrupt the boot process.

Main Menu> boot pri #Boot from the primary boot disk.

Interact with the IPL? Y #Do interact with the IPL/ISL.

ISL> hpux ll /stand #Shows the content of the boot filesystem /stand

ISL> hpux -is /stand/vmunix.prev #Boot from the original kernel and goto single user

Step 2: Moving the Original Kernel Back into Place
After booting the system, you may wish to make the original kernel the default so future reboots can proceed without any intervention from the administrator:

#mount /usr
# cd /stand #Move to the /stand directory.
# mv system.prev system #Move the original system file back into place.
# kmupdate /stand/vmunix.prev #Move the original kernel back into place.
# shutdown â ry 0 #Reboot the system with the original kernel.



**Note 1: If â cd â or â mvâ or â kmupdateâ command not work after booting the system into single user mode mount /usr directory.

#mount /usr

**Note2: To Shows the content of the boot filesystem /stand give the following command.This is useful if the kernel cannot be found.

ISL> hpux ll /stand

Thanks
Minhaz