[CentOS] detecting boot order

Fri Aug 29 19:33:29 UTC 2008
Mark Belanger <mark_belanger at ltx.com>

William L. Maltby wrote:
> On Fri, 2008-08-29 at 13:58 -0400, Mark Belanger wrote:
>> Given that I have a machine with possibly multiple disks, each of
>> which is bootable(has an MBR)....
>> Is there a command that will query the BIOS and tell me which disk
>> is the default boot disk.  BTW - this is x86.
>> The goal is to remotely reboot the workstation into the desired
>> disk(which contain different centos versions).
> Having said all that, why do you want to do it that way? It's much
> better (and easier for you to accomplish your stated goal) by setting up
> a single (and a backup, *maybe* - there's a couple more tricks needed
> for that if using LVM) boot partition that loads and handles the
> differences you need to support. Make your boot partition(s) larger, if
> needed, to support multiple versions of kernels, initrd, config.* and
> system maps. The using the "default" command of grub you can point to a
> boot configuration that will load different kernels, pass different
> initrds, mount different roots and even load different OSs (see the
> "chain" descriptions in "info grub").

Thanks for the info - very detailed.

I'm trying to find a one-size-fits-all method that is grub based.  We
have many different configurations here so I want something that
can work with any of them.

So far, the best thing I've seen is sfdisk -l which will show me
bootable partitions.  In a pinch, I could mount all the bootably parts
and scriptify the altering of grub.conf


Mark Belanger
LTX Corporation