[NBLUG/talk] RAID?

[Kyle Rankin]

On Mon, Dec 31, 2007 at 10:37:00AM -0800, Lincoln Peters wrote:
> On Dec 31, 2007 10:23 AM, Kyle Rankin <kyle at nblug.org> wrote:
> > Just wanted to comment on this point, actually these days mdadm can grow
> > RAID-5 arrays by adding a partition (and there was a tool to do it on
> > old-style linux software RAID as well). I've successfully done it to grow
> > RAID5s both with the old-style tool and with mdadm as part of testing for
> > Knoppix Hacks and while it took some time it did work.
> 
> Cool.  I set up that RAID system a few years ago, but I haven't been
> paying attention to new developments in the Linux RAID tools (since
> what I had worked so well).
> 
> Now if only I could have a setup that would provide a comparable blend
> of capacity and redundancy to RAID-5, without requiring all the disks
> to be the same size.  Do you know of a way to do THAT?
> 
> 
> -- 
> Lincoln Peters
> <anfrind at gmail.com>
> 

The disks don't have to be the same size, but it's true that the partitions
do have to be the same size (or if one is larger, you will lose that extra
size). In the past I've had success with migrating to new RAID-5 arrays
though when I've needed more capacity. Basically I buy a new set of
drives that match or are larger than some of the larger drives that
were in my patchwork RAID5 I currently had. Then I connect just enough
drives to create the degraded RAID5, copy the data to the new array,
and then add the final drive after the others are removed.

-- 
Kyle Rankin
NBLUG President
The North Bay Linux Users Group
http://nblug.org
IRC: greenfly at irc.freenode.net #nblug 
kyle at nblug.org