[BlueOnyx:11170] Re: MDADM / FDISK problem

[Michael Stauber]

Hi Richard,

> One other thing I tried was to manually build the partitions.  Copying the 
> partition table from sda to sdb is fine for the first partition, but won't 
> let me create the second partition with a sector starting on block 64, so 
> I'm still stumped.

You see, the partition starting and ending on block 64 is a thing
between Disk Druid and Fdisk. For Disk Druid it was perfectly legit, but
fdisk refuses to let you do that.

Try this then to create partitions on /dev/sdb that exactly match the
ones already present on /dev/sda:

sfdisk -d /dev/sda | sfdisk --force /dev/sdb

Afterwards it may be necessary to manually add the partitions of
/dev/sdb back to the RAID array in order to trigger the rebuild.

Judging from your earlier message which showed the RAID1 layout, it
would be these commands:

mdadm --add /dev/md0 /dev/sdb1
mdadm --add /dev/md1 /dev/sdb2

Once you have added sdb back to the array, the RAID rebuild will start
automatically.

For things like this I found this "cheat-sheet" quite useful:

http://www.ducea.com/2009/03/08/mdadm-cheat-sheet/

-- 
With best regards

Michael Stauber