I have two drives in a software mirror. Other than setting the bios to boot from the second drive, is there any way to confirm that grub is installed properly on the second drive? -- Bowie
When installing CentOS - sometimes the RAID-1 /boot partition, usually
/dev/md0 fails to boot.
The bug is known and exists on the bugtracker for CentOS as well as RedHat.
The fix is to re-install GRUB on on each partition of the RAID-1 array.
I think you could use the same method to answer your question.
1. boot server w/ any 'Disk-1' of an installation set
at boot prompt type 'linux rescue'
Continue boot.
2. First double check your disks with the mdadm utility
# mdadm -QD /dev/md0
Make a note of every disk (you can ignore the spare)
example: /dev/{sda1, sdb1, sdc1, sdd1, sde1}
3. drop into the GRUB prompt
# grub
grub> device (hd0) /dev/sda
grub> root (hd0,0)
grub> setup (hd0)
<repeat for each drive in the array>
grub> device (hd0) /dev/sdb
grub> root (hd0,0)
grub> setup (hd0)
Rinse - Repeat, etc.
4. exit from GRUB and reboot.
If you then want to test it, disconnect one of your drives - or just
drop into grub at boot
and tell it to boot from the partition of another drive.
-Peter
2008/6/9 Bowie Bailey <Bowie_Bailey at buc.com>:> I have two drives in a software mirror. Other than setting the bios to
> boot from the second drive, is there any way to confirm that grub is
> installed properly on the second drive?
>
> --
> Bowie
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Peter Farrell wrote:> > 2008/6/9 Bowie Bailey <Bowie_Bailey at buc.com>: > > I have two drives in a software mirror. Other than setting the > > bios to boot from the second drive, is there any way to confirm > > that grub is installed properly on the second drive? > > When installing CentOS - sometimes the RAID-1 /boot partition, usually > /dev/md0 fails to boot. > > The bug is known and exists on the bugtracker for CentOS as well as > RedHat. > > The fix is to re-install GRUB on on each partition of the RAID-1 > array. > > I think you could use the same method to answer your question.<SNIP>> If you then want to test it, disconnect one of your drives - or just > drop into grub at boot > and tell it to boot from the partition of another drive.I already know how to install grub on the second drive. The issue is that this is a production server and I'm trying to avoid rebooting it if possible. I'm looking for a way to determine whether grub is installed on a drive WITHOUT having to actually attempt to boot from it. If I redo the installation, then I can be sure it's installed, but if it's already there, I'd rather leave it alone. There's no point in messing with it if it's already installed. -- Bowie