RAID Recovery

[Nigel Wade]

Jason Hoffert wrote:
> I had setup software RAID on my Fedora Core 3 box with 3 RAID1 partition
> sets. Well, one of my SCSI drives failed. I have now replaced the HD,
> and the server is up but how do I rebuild the arrays? I've looked into
> raidtools and it seems with raidhotadd it would be easy, but that's not
> part of Fedora. Is there any quick and easy command using mdadm that
> will repartition the new drive and re-create my arrays? Can I just
> install raidtools and run their utilities without damaging my
> partitions?
> 
>  
> 
> Thanks!
> 
> 
> 

You will need to partition the drive manually. But sfdisk makes this easier 
as the output of sfdisk can be formatted in such a was as to be used as the 
input to sfdisk to partition a disk. The incantation used to be:

# sfdisk -l -uS -d <existing disk> | sfdisk <new disk>

where <existing disk> is the device of the disk you want to have copied, and 
<new disk> is that of the new disk you are adding to the system. Don't get 
them the wrong way around ;-). This is what I have noted down for use on 
RH7.3, so check carefully to see if sfdisk has changed.

After you've partitioned the drive, use mdadm to add the partitions to the 
RAIDs. After you've added the partitions check the status of each RAID to 
see if it's being re-built on the new disk.


-- 
Nigel Wade, System Administrator, Space Plasma Physics Group,
             University of Leicester, Leicester, LE1 7RH, UK
E-mail :    nmw at ion.le.ac.uk
Phone :     +44 (0)116 2523548, Fax : +44 (0)116 2523555