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@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 _______________________________________________ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos