[TriLUG] Setting Up RAID-5

[Ed Hill]

On Thu, 07 Dec 2006 23:07:29 -0500 Jason Tower <jason at cerient.net>
wrote:
> 
> there are probably workaround for these issues, or if they don't
> bother you then knock yourself out with software raid.  i use it
> myself if circumstances justify it.  but i've built enough systems to
> know that hardware raid exists for a reason.  if you want to do the
> job right get a 3ware card and sleep peacefully.


Hi folks,

My last employer used and continues to use 3ware RAID cards (7xxx,
8xxx and and 9xxx series) on about a dozen NFS servers.  They generally
perform well but they are not perfect.  Some are picky about the
motherboards they will work with.

About two months ago, the then-largest NFS server in the rack (a few TB)
suddenly stopped working.  There was a glitch with the 3ware card and
it caused array corruption.  When the system was rebooted the card
refused to recognize the existing array.  Multiple attempts were made
(with the help of 3ware support and swapped 3ware cards) to fix the
system but the data was eventually declared a total loss and the array
reformatted and put back into use.  Some folks were quite disappointed
to learn that all their files on that machine were gone forever.

I have no idea how often this sort of thing happens.  It was only one
system out of about a dozen.  I'm sure that's not a representative
sample.

But the lesson was learned.  Don't for a moment think that you are 100%
safe with a 3ware RAID setup, even with hot spares and an attentive
admin staff.  If you really value your data then there are no
substitutes for completely separate (preferably off-site) backups.

Period.

Ed


-- 
Edward H. Hill III, PhD  |  ed at eh3.com  |  http://eh3.com/
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 189 bytes
Desc: not available
URL: <http://www.trilug.org/pipermail/trilug/attachments/20061207/27b95270/attachment.pgp>