RAID5 capacities / usable drive space ...

[Andy Farkas]

On Tue, 13 May 2003, Marc G. Fournier wrote:
> On Wed, 14 May 2003, Greg 'groggy' Lehey wrote:
>
> > Hmm.  You know some interesting someones.
>
> Yup ...
>
> > Yes, it doesn't make sense to have a RAID-5 volume with less than three
> > drives, but in degraded mode it'll run with two.  Or it should, bar
> > implementation constraints.  And theoretically you could hot swap them.
>
> 'K, I'm going to test the 'theory' out tomorrow just to make double sure
> about the 3->2 drive configuration ... since you already know the vinum
> internals, I'm more worried about how hardware RAID will handle things ...

I had a vinum raid-5 volume lose a disk a few months ago. vinum handled it
fine for the couple of weeks while waiting for a replacement (including
reboots).

Adding in the replacement disk is a whole other story. It may well be
worth practicing. Documentation in this area is lacking.

--

 :{ andyf at speednet.com.au

        Andy Farkas
    System Administrator
   Speednet Communications
 http://www.speednet.com.au/