RAID-1 with one disk causes filesystem to be corrupt?
 

Hello,

I created one formatted disk (/dev/sda3) and I started RAID-1 with one disk on it. Everything went alright and raid was started fine and all.

I stopped the raid and tried to mount /dev/sda3 but I got the following error message now:

"unknown filesystem type 'mdraid'

Can someone please tell me why am I seeing this error message and why the filesystem is corrupt after stopping the raid?

Thank you

Hi There,

If you have a Signal RAID-1 Device it should be under /dev/md? since access to the raid device is via the raid sub system. So /dev/sd would be the part of the raid device ( in your case the only device)

In other words, you don't mount /dev/sda3, you mount /dev/md1 (or /dev/md2 or whatever), like
after you activate the RAID set with mdadm

Thanks for the reply. Well, okay, I understand that...I mounted /dev/md# when the raid was running, BUT I *stopped* the raid (mdadm --stop --scan) and then tried to mount the lower level device (/dev/sda#) which failed.

Any ideas?

Yes, you can't do that. See above, and BTW your filesystem isn't corrupted, it is "mdraid", meant to be mounted as a raid device by mdadm, not mount.