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Widescreen
October 19th, 2008, 01:03 AM
Although I've been a Solaris system administrator for over 15 years, I'm using Ubuntu to power a RAID-1 server for home. I want this to be a fully bootable mirror. The RAID is working fine, but I can't get Ubuntu to load up all the way if I disconnect the first drive.

For some background...

I used the alternate desktop, and created three RAID-1 partitions during the installation:
- one for /boot
- one for /
- one for file system to be shared out to the rest of the LAN

I added GRUB to both drives (grub-install /dev/sda1 and grub-install /dev/sda2). At first, the mirror drive dropped me into initramfs.

So, I reattached hd0/sda1 then I modified menu.lst and copied

title Ubuntu 8.04.1, kernel 2.6.24-21-generic
root (hd0,0)
kernel /vmlinuz-2.6.24-21-generic root=/dev/md1 ro quiet splash
initrd /initrd.img-2.6.24-21-generic
quiet

into a new set of lines...

title Ubuntu 8.04.1, kernel 2.6.24-21-generic
root (hd1,0)
kernel /vmlinuz-2.6.24-21-generic root=/dev/md1 ro quiet splash
initrd /initrd.img-2.6.24-21-generic
quiet

Now the server boots up to the Ubuntu logo, but it doesn't go anywhere else.

So, obviously I am missing something but I'm not sure what. mdadm shows that the mirror is up and running, and the fact that I can get to the Ubuntu logo shows that it is indeed booting from the secondary drive. I'm guessing that it's bombing out when it attempts to mount root (/) from hd1 instead of hd0, but I don't know what to look at to determine where the problem is.

Can anyone give me a hint of what I must have missed?

Here are some other tidbits of information that might help.

~$ cat /boot/grub/device.map
(hd0) /dev/sda
(hd1) /dev/sdb

~$ cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md2 : active raid1 sda4[0] sdb4[1]
604967616 blocks [2/2] [UU]

md1 : active raid1 sda3[0] sdb3[1]
19534976 blocks [2/2] [UU]

md0 : active raid1 sda1[0] sdb1[1]
128384 blocks [2/2] [UU]

unused devices: <none>

~$ df -k | grep "/md"
/dev/md1 19380644 2334484 16069412 13% /
/dev/md0 124323 24601 93303 21% /boot
/dev/md2 600201168 202296 569750492 %1 /home