On Thu, 11 Sep 1997, Chris Wedgwood wrote:
> I would think a mirror large enough to require raid0 (for speed) is
> probably large enough that you would really want raid5...
Depends. Raid 5 is less useful if you have heavy write loads or do
not have a write back cache big enough to avoid saturating under
peak write loads. Raid 0, 1 and 5 are all useful in their place.
Agreed. But I was talking about the specific case of an ftp/www mirror. I
don't operate one of these, so I don't speak from experience, but I would
guess reads are maybe one hundred times more prevalent than writes for this
type of use.
raid0 has better write (and read) performance, but a large array could
conveiable have a high failure rate. (MTBF per drive / no. of drives).
raid1 is a tad expensive when you have 10+GB of data or so. (Actually, maybe
this was once true, but disk is cheap nowdays).
-Chris