[rescue] RAID level 6 - any experiences?

[Gregory Leblanc]

On Mon, 2002-02-25 at 19:38, Patrick Giagnocavo wrote:
> I got a rackmount disk shelf from Mike N.
> 
> Already had the Mylex RAID controller.
> 
> I understand that RAID6 can handle more than one drive failure and
> keep going.
> 
> Does anyone have any experience with this, or should I bite the bullet
> and go RAID 10?

Hmm, RAID 6 is some Mylex name for a RAID level, let me see what it
is...

Oh, well, not quite Mylex specific.  It's RAID 5, only with twice as
much parity, using two different algorithms.  Woah, ick, that'll be SLOW
for writes.  If you've got 4 disks, it will give you the same capacity
as RAID 10, except that it will be really dog-assed slow, even for reads
(assuming that your controller can do read-balancing across a RAID1
mirror).  You start gaining a little bit of space back with more disks,
but it's slow to gain.  If you raid controller goes tits-up, you're
screwed, and won't be able to recover your data unless you can find
another card just like it.  At least with RAID 5 or 10 you can find a
Linux box and restore the data that way.  I'm always a fan of RAID 10,
if you can afford it.
	Greg

-- 
Portland, Oregon, USA.