recover mirror from /dev/sda1 crash in Fedora Core 3

[dan dobbs]

Hey gang. I have a server set up with two SATA drives operating in a software mirror. The primary HD (/dev/sda1) died. I replaced it, and it wouldn't boot. I even tried fdisking the new drive, doing an mkfs and copying all the partitions and info from /dev/sdb to /dev/sda, but I still couldn't get it to boot, and grub-install wasn't cooperating, either (I had /boot and / on different partitions, so when I CHROOT'ed, they couldn't see each other).

Finally, I copied all the info using an NFS mount to another server, and nuked it. There's got to be an easier way....anyone have the silver bullet? :>)

Thanks in advance,

-dd

[Stuart Browne]

If using Software RAID mirroring, you should be able to boot up using rescue media, and use the MD commands to re-mirror the RAID set from the good disk.

Theoretically, if there wern't any file-systems on the new disk you put in, it should have booted from the other one (but I think the '/boot' filesystem can't be MD's? Not 100% sure).

http://www.tldp.org/HOWTO/Software-RAID-HOWTO.html

Section 8.

[Steven E. Protter]

This is a good reason why it is needed to test the boot off the alternate mirror drive.

In theory, you should have been able to boot off the mirror drive. Something went wrong in the installation or after that point.

SEP

[dan dobbs]

Simply put, I don't think the server I'm using is that smart. It appears that it only looks at disk #1, and there isn't anywhere in BIOS where I can say 'hey man, look at the *other* disk'.

But, I found a good answer on Google, as per usual, about an hour too late. Here's the page: http://radu.rendec.ines.ro/howto/raid1.html . Long story short, if you boot with a rescue disk, and monkey with your raidtab file, you can mount your mirror and start re-syncing.

I hope I don't have to put it to the test anytime soon. :>)

Cheers,

-dd