Server Fault is a question and answer site for system and network administrators. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I have a 4 drive RAID array. A small part of each disk is partitioned and used in RAID 1 for /boot. Everything else is RAID 5. When I start the computer GRUB2 shows up and I can use its command line and view each of my RAID arrays (ls (md0)/ or ls (md1)/etc, for instance). However, when I actually try to have GRUB2 boot the system I get these errors:

modprobe: FATAL: Could not load /lib/modules/2.6.35-22-generic-pae/modules.dep: No such file or directory

mount: mounting /dev/disk/by-uuid/[uuid] on /root failed: Invalid argument
mount: mounting /dev on /root/dev failed: No such file or directory
mount: mounting /sys on /root/sys failed: No such file or directory
mount: mounting /proc on /root/proc failed: No such file or directory
Target filesystem doesn't have requested /sbin/init.
No init found. Try passing init= bootarg.

Here are the GRUB2 commands that are being run:

insmod raid
insmod mdraid
insmod part_msdos
insmod ext2
set root='(md0)'
search --no-floppy --fs-uuid --set [uuid]
linux /vmlinuz-2.6.35-22-generic-pae root=UUID=[different uuid] ro quiet
initrd /initrd.img-2.6.35-22-generic-pae

I have tried

fsck /dev/md0
fsck /dev/md1

and both arrays come out clean. I've booted to the CD and looked everywhere I can think of for a discrepancy that would cause GRUB2 to fail to boot. Using the GRUB2 command line and the CD command line everything appears to be in working order. Both RAID arrays show up active and not degraded. What is keeping GRUB2 from being able to mount and boot the system?

share|improve this question

Ah, now I'd probably be more tempted to install GRUB onto the actual disks, not onto the md0 device.

grub> root (hd0,0)
grub> setup (hd0)

grub> root (hd1,0)
grub> setup (hd1)

Because that way, the bootloader sees the disks as disks first, and not have to load a module to make it work. It's also backwards compatible with GRUB, compared to GRUB2.
It's a bit like how you have a separate /boot partition that's RAID1.

share|improve this answer
Should I get rid of the RAID 1 md0 array? – Brad Oct 27 '10 at 14:36
No, keep that, because it's a good way to protect your data.. But you can get grub to access the disk beneath the array. – Tom O'Connor Oct 27 '10 at 15:12
grub> setup no longer seems to be a command. Is there a replacement in GRUB2? – Brad Oct 27 '10 at 21:49
That is a good question. I'm not sure. – Tom O'Connor Oct 28 '10 at 8:58

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.