[Lustre-discuss] Hardware or software RAID?

[Jeff Layton]

Andreas Dilger wrote:
> There are a number of large clusters (TACC Ranger in particular) that use
> software RAID on JBODs, but the majority of systems use hardware RAID in order to
> maximize performance (at an increased cost of course).
>
> These days I would tend to recommend using RAID-6 over RAID-5 just because
> the large disks available take a long time to rebuild, and there is a
> non-zero risk of a second disk failing during that time.
>   

What about using more, but smaller raid groups? For example,
perhaps 4-5 drives in a RAID-5? That way if a disk fails, the
rebuilds are faster since there is less data?

Jeff