Grub Doesn't Recognize RAID For Repair

FireDemonSiC · 03-07-2011, 02:18 AM

Last night I upgraded my 10.04 Ubuntu install to 10.10 and guess what? It broke the boot loader. Grub falls to a recovery shell at boot so at the moment I have NO OPERATING SYSTEM.

No problem I can fix that with the LiveCD.

So I popped in the live CD, installed kpartx so I can properly read my RAID array and verify this in gparted. 4 Linux partitions and two Windows so we should be good to go.

Quote:

ubuntu@ubuntu:~$ sudo grub
Probing devices to guess BIOS drives. This may take a long time.
Unknown partition table signature
Unknown partition table signature

[ Minimal BASH-like line editing is supported. For
the first word, TAB lists possible command
completions. Anywhere else TAB lists the possible
completions of a device/filename. ]
grub> root (hd0,3)
root (hd0,3)

Error 22: No such partition
grub> root (hd0)
root (hd0)
grub> root (hd1)
root (hd1)
grub> root (hd2)
root (hd2)
grub> root (hd3)
root (hd3)
grub>

As you can see, grub isn't reading the RAID array. It's still recognizing 4 individual drives. How do I correct this?

I am using software RAID with the onboard NVRaid controller of my 780a motherboard.

EDDY1 · 03-07-2011, 04:21 AM

Grub2 lists devices as sda, sdb
You may have to mount all partitions and do
"os-prober"
"update-grub"
I am told "os-prober is unnecessary, but I still include it.
http://karuppuswamy.com/wordpress/20...rescue-prompt/

FireDemonSiC · 03-08-2011, 01:36 AM

I tried OS prober, which returned:

Quote:

ubuntu@ubuntu:~$ sudo os-prober
/dev/mapper/nvidia_fggfjajh1:Windows 7 (loader):Windows:chain
/dev/mapper/nvidia_fggfjajh2:Windows 7 (loader):Windows1:chain
/dev/mapper/nvidia_fggfjajh5:Ubuntu 10.10 (10.10):Ubuntu:linux
ubuntu@ubuntu:~$

Then of course updateb grub, which returned:

Quote:

ubuntu@ubuntu:~$ sudo update-grub
Searching for GRUB installation directory ... found: /boot/grub
Searching for default file ... Generating /boot/grub/default file and setting the default boot entry to 0
Searching for GRUB installation directory ... found: /boot/grub
Testing for an existing GRUB menu.lst file ...

Could not find /boot/grub/menu.lst file. Would you like /boot/grub/menu.lst generated for you? (y/N) n

Not creating /boot/grub/menu.lst as you wish

So it looks like It's not recognizing my 200MB ext2 boot partition, despite the fact I have it mounted and can access it from the desktop. Where do I go from here?

it appears that the boot partition IS recognized through gparted (Since I installed kpartx to properly read my RAID array). Should I attempt to mount It's /dev/mapper location as /boot?

FireDemonSiC · 03-08-2011, 01:45 AM

I tried the above fix. I even tried:

Quote:

ubuntu@ubuntu:~$ sudo mount /dev/mapper/nvidia_fggfjajh3 /boot

Grub is still not recognizing the array. My grub install resides on (hd0,3). But grub is still seeing (hd0-3) so It's seeing 4 seperate disks instead of the array. I can't continue with repairing the bootloader until I figure out why It's doing this.

FYI, I manually went and checked and /boot/grub/menu.lst IS there. It just isn't seeing it because of the no RAID support.