please help, I've screwed up my RAID 1 install
From: Matthew Simpson <hidden>
Date: 2004-01-04 02:39:15
Hello everyone, I've really buggered up a RAID 1 install, and I need some
help.
My first mistake was when I was setting up the partition tables, the HOWTO I
was reading mentioned to set the partition type to 0xfd in fdisk. I've
always used 82 and 83 so I assumed that it may be prudent to actually type
0xfd into fdisk instead of just fd... which fdisk promptly accepted as "00"
[empty]. I didn't notice that, though.
I started out originally with the entire disks partitioned this way, and I
could read/write data, but I couldn't boot from /dev/md0 using the boot
floppy I set up.
I then changed it so that I have hda1, hda2, and hda3 [and corresponding
hdc1, hdc2, hdc3]. Hda1/hdc1 are still erroneously marked 0xfd, and are
80GB. Hda2/hdc2 are marked 83, Hda3/hdc3 are marked 82 [swap]. I'm booting
into hda2 from the floppy, and then I can:
mkraid /dev/md0
mount -text3 /dev/md0 /drives/md0
and it works.
[you can see my /etc/raidtab at the bottom of this message]
The problem is, if I reboot the machine, then I cannot mount /dev/md0 again
until I do a mkraid /dev/md0 --really-force and rewrite the superblock. I
do not lose any data, but I know this "can't be good" [tm].
What can I do to fix this? I've tried setting the partition types for
hda1/hdc1 to the correct "fd" type, but fdisk complains "Partition 1 does
not exist yet".
Also, it is possible to boot from a RAID device, is it not? I assume it
wasn't working before because of the superblock problem.
My /etc/raidtab:
raiddev /dev/md0
raid-level 1
nr-raid-disks 2
nr-spare-disks 0
chunk-size 4
persistent-superblock 1
device /dev/hda1
raid-disk 0
device /dev/hdc1
raid-disk 1