[Solved] Re: FC5 S/W Raid Rebuilding to Infiinity(and beyond!)

[Sean Bruno]

> You have found yourself in the same situation I found myself in recently. 
> Actually my situation was slightly different, but the resulting problem is the 
> same. In my case at re-boot md decided that one partition of a mirror was out of 
> sync, and so initiated a re-sync with the other partition. However, the 
> partition which was active contained a bad sector, so the re-sync failed, over 
> and over and over..., just like yours is doing.
> 
> In order to fix my system I used the following steps.
> 
> The first step is to take the offending filesystem offline. Then I copied the 
> existing partition onto the good disk using dd, with the noerror option so it 
> would continue past read errors. In my case I knew that the read error was not 
> part of the actual filesystem in use because it passed fsck. When the copy was 
> complete I ran fsck on the new filesystem just to be sure it had copied ok.
> 
> After this I created a new RAID consisting of just the good partition (in my 
> case the RAID was md1 and the new partition was sda3):
>   # mdadm -C /dev/md1 --force -n 1 -l 1 /dev/sda3
> 
> As a temporary fix, until a new disk arrived, I ran
>    # e2fsk -c -d -f /dev/sdb3
> to mark back blocks (sdb3 was the failing partition).
> Then I ran:
>    # mdadm --zero-superblock /dev/sdb3
> to remove the md superblock from the partition so it was no longer part of a RAID.
> 
> Finally, I used mdadm to add the dodgy partition back into the RAID:
> 
> # mdadm -a /dev/md1 /dev/sdb3
> 
> and to grow the RAID to 2 partitions:
> 
> # mdadm --grow -n 2 /dev/md1

Thanks for the assistance with this Nigel.  I was able to recover from
this 'double' failure with your procedure.  I had purchased 2 new disks
in order to replace the failed drives and I am back up at this time.

Sean