Grub or Lilo

[krkinder]

Couple of questions. It seems that SB's kickstart installs both Grub and Lilo. Does anyone know which they boot from? I'm not sure there is a way to tell other than poking around in the MBR, which I'm not inclined to do. Since both our installed, it depends on SB's RedHat kickstart.

Secondly, I was wondering if anyone has had any experienced to share about upgrading kernels on SB. If the box doesn't go back up, what are one's options?

-Ken

[spoon]

Given that both should be configured and both will over write the MBR, it doesn't really matter. :)

Secondly, the only option you have is to submit a ticket and have someone go reset the box for you.

What I'd reccomend doing is using lilo and use the -R feature. The -R arg will let you specify a command line to use at the prompt the next time the server boots. So...

1) keep your working kernel on the system! Always use "rpm -ivh" if installing a kernel RPM, or use a new filename for your new kernel/initrd.
2) make sure you've got lilo setup to ask for a prompt, and give it a timeout of around 10 seconds or so
3) setup a lilo entry for the new kernel.... keep the default boot option set for your current, working kernel
4) run "lilo -R <new label>"
5) reboot the box

If the new kernel fails to come up, you can always use the Rapid Reboot feature to powercycle the system and bring it up with the old, known-good working kernel. If the new kernel is good, you should be back on the box in no time.

I would imagine that GRUB has something similar, but I'm not familiar with all of its options.

[krkinder]

Hey spoonman, are you at work? Can you hear NPR from the down the hall? :)

I'm a grub newbie too, but given that it isn't constantly rewriting the MBR, I'd just prefer to just continue using it if it's setup in the kickstart well enough.

Regarding the troubleticket, what I'm worried about is that the list of issues ServerBeach's support claims to address seems to have boot-related problems intentionally left out, such as lilo problems. (Sometimes lilo doesn't seem to write to the MBR right -- for example).

-Ken

[knightfoo]

All of the SB servers use GRUB by default. Lilo might be installed on some of the RedHat servers for dependency issues .. I'll have to look into this. GRUB does have a fallback option, so if one kernel image fails to boot then it will try the other. Unfortunately most people upgrade the kernel and leave something out, so it boots but they don't have network access .. GRUB can't do anything about this.

You can check if GRUB or LILO is in the MBR by doing this:

dd if=/dev/hda bs=512 count=1 | strings

-knightfoo