[CentOS] Linux Software RAID 1 - Unequal Sized Hard Disks

Thu Oct 18 15:55:01 UTC 2012
Bowie Bailey <Bowie_Bailey at BUC.com>

On 10/18/2012 11:29 AM, Manish Kathuria wrote:
> Has anyone created or rebuilt a Linux Software RAID having mirrored
> partitions on unequal sized hard disks ? There is  a CentOS 5 server
> having two 400 GB hard disks with five mirrored partitions (software
> RAID 1) and one of the hard disks is dying. Since new 400 GB HDDs are
> not available here, we are exploring the possibility of replacing the
> faulty hard disk with one of a higher capacity (500 GB or more). And
> once it is fully replicated, we plan to replace the other 400 GB HDD
> also with another hard disk of the same higher capacity.
> Just want to know if anyone has done something similar and what are
> the chances of success (or data loss) ?

I've done this with a 3-drive software raid 1.  It originally had 750GB 
drives which I replaced with 1TB drives.

Swapped them out one by one configuring them with the exact same 
partition structure as the others and allowing each one to resync before 
continuing.  Once they were all in, I resized the filesystem (ext3) to 
take advantage of the extra space.