[ale] raid suggestions

[Pat Regan]

On Fri, 10 Feb 2012 04:44:38 -0500
Jim Lynch <ale_nospam at fayettedigital.com> wrote:

> Has the concern about the possibility of the hardware controller 
> breaking and being out of production been eliminated?  

Whether the card is out of production or not may not matter much in the
middle of the day when the controller decides to fail.  You'll still
either have to own a spare or you'll have to be able to actually
purchase one nearby.  Depending on your scale, buying that spare may be
a sizable amount of your server budget.

Almost all the arguments I've seen in favor of using hardware instead of
software RAID are either completely untrue or were a true for a short
window around 10 years ago.

> That of course can be alleviated by proper backups.  I always thought 
> that was somewhat meaningless in a lot of cases 'cause I'd think many 
> raid installations were to support a backup set of drives.  Not all,
> of course, but surely that's a common purpose for a raid set.

RAID is not a replacement for backups.  Your RAID only helps protect
you from disk failures and reduce the risk of downtime.  It won't
protect you from many kinds of data corruption or from user error.

Pat