topic Re: Kernel Change - Reboot Later in Operating System - HP-UX

Kernel Change - Reboot Later

brian_31 — Thu, 29 Jun 2006 13:52:08 GMT

I have two questions on kernel change

1. I want to make changes on the kernel (using SAM) and then reboot later(may be weekend). I know this is possible, but when i am done with the changes it says (are u sure and it also says the system will reboot). i do not want to reboot now. Can i select "do not move the kernel into place" and reboot later?

2. suppose i want to make some more changes after i select "do not move the kernel into place" how would i do it?

Thanks

brian

Re: Kernel Change - Reboot Later

Sandman! — Thu, 29 Jun 2006 14:03:04 GMT

Brian,

If you want to stage changes to the kernel and defer rebooting to a later time, I would suggest using the command line tools instead of SAM as they give you greater control. What server and OS are you using?

~cheers

Re: Kernel Change - Reboot Later

Marvin Strong — Thu, 29 Jun 2006 14:05:26 GMT

well you can make the kernel manually without using sam.

cd /stand/build
cp ../system system
/usr/lbin/sysadm/system_prep -s system
vi system and make your changes
mk_kernel -s system

Then move these into place and reboot later.

mv /stand/system /stand/system.prev
mv /stand/vmunix /stand/vmunix.prev
mv /stand/build/system /stand
mv /stand/build/vmunix_test /stand/vmunix
shutdown -r now

Re: Kernel Change - Reboot Later

Sundar_7 — Thu, 29 Jun 2006 14:22:48 GMT

Brian,

I would not move the kernel using the mv command.

Assuming you are running 11.11, the followign is the process for rebduiling the kernel

# cd /stand/build
# /usr/lbin/sysadm/system_prep -s system
# kmtune -s = -S system
# mk_kernel -s system

Now if you wanna move the kernel manually, the command kmupdate should be used

# kmupdate

This will create a .update_ux file in the /stand directory which is referred upon shutdown time.

Sundar.

Re: Kernel Change - Reboot Later

Steven E. Protter — Thu, 29 Jun 2006 14:37:23 GMT

Shalom brian,

Even with sam you can choose not to boot.

But the best practice is to do everything, including kmupdate and then not boot the system until planned.

This does risk an accidental or power caused boot to mess things up, but its a perfectly legitimate practice.

SEP

Re: Kernel Change - Reboot Later

Bill Hassell — Thu, 29 Jun 2006 19:17:45 GMT

If I rememeber right, SAM had a bug where it would reboot anyway even if you said to build the kernel and NOT reboot -- it may be fixed by now but I would not trust this choice on a production machine. Note also that if you replace the vmunix file, several commands will start failing, like ipcs. Some commands depend on looking inside the kernel as well as looking into the vmunix file and they must match. Use the comand line interface and leave the new kernel file as is until you reboot.

Re: Kernel Change - Reboot Later

Sandman! — Fri, 30 Jun 2006 06:05:38 GMT

Follow the steps listed by Marvin, with one exception. Replace the "mv" with "cp" as some of the commands like ipcs, lanscan, lanadmin etc. will fail if they can't lookup the kernel. Don't attempt to move the new kernel and the system file manually, instead use "/usr/sbin/kmupdate" for this i.e.

replace the commands below...
# mv /stand/system /stand/system.prev
# mv /stand/vmunix /stand/vmunix.prev

...with
# cp /stand/system /stand/system.prev
# cp /stand/vmunix /stand/vmunix.prev
# cp -R /stand/dlkm /stand/dlkm.prev

and the ones below...
# mv /stand/build/system /stand
# mv /stand/build/vmunix_test /stand/vmunix

...with
# kmupdate

~cheers