Software RAID Problems

[mcvaughan]

I created a simple RAID 0 array using mdadm. For some reason, I have two md devices, instead of one (md0). I have one incomplete array and one complete. I don't know if I'm missing something here, but I cannot remove the incomplete array. I don't know why my array became md1. Here is what it looks like:

Personalities : [raid1]
md1 : active raid1 sdc1[0] sdd1[1]
17775808 blocks [2/2] [UU]

md0 : active raid1 sdd[1]
17783168 blocks [2/1] [_U]

---

md1 is the array I created as md0, but something's hosed here. It's been a long time since I've done any admin stuff on linux, so go easy on me. ;-)


Thanks.

[syoung]

I'm having the same problem, although with RAID1. I'm using Edgy server. I've tried configuring the RAID1 array with the installer and manually with mdadm.

The array breaks down on reboot, I think because there are two RAID devices going after it. Long story short, the superblock of one of the partitions gets hosed.

I think there might me some discrepancy between mdadm.conf in initrd and the local fs file. See http://ubuntuforums.org/showthread.php?t=287723. I'll let you know if I have any luck.

[syoung]

Yes, that might be your problem. As in the thread I posted above, use mdadm --detail --scan to write your /etc/mdadm/mdadm.conf file. Then dpkg-reconfigure mdadm so initrd is regenerated.

You should then have only one array. You can verify that it worked by the following:


mkdir tmp
cp /boot/name-of-initrd-image ~/tmp/initrd.gz
cd tmp
gunzip initrd.gz
cat initrd | cpio -id


That will create a directory tree in ~/tmp that contains initrd's copy of mdadm.conf. Make sure it matches the one you created manually.