Re: RAW devices

From: DA Morgan <damorgan_at_psoug.org>
Date: Wed, 22 Mar 2006 12:32:51 -0800
Message-ID: <1143059570.335042@yasure.drizzle.com>

Joel Garry wrote:

>> Just received my new NetApp 270C yesterday: Dual filer heads and a
>> TB of disk. It took less than 4 hours to build a 4 node cluster on it.

>
> Software RAID-4? How long does it take to rebuild parity when you lose
> the parity drive and another drive? How do you know how long the
> batteries will last in nvram when the batteries in your ups die?
>
> (One starts thinking about these things when one works on systems more
> than 2 years old and has to deal with the consequences of no one
> watching the batteries and arrays of inexpensive disks manufactured in
> one batch reaching their time of failure, which is much less than the
> rated mtbf. But that is too late, of course).
>
> jg
> --
> @home.com is bogus.
> It is now a crime to delete files.
> http://catless.ncl.ac.uk/Risks/24.20.html#subj6

A production system should not rely on batteries. It should rely on dual diesel generators with fuel purchased from two independent companies. And the rest of what this implies.

I've never lost a parity disk in production where we didn't have it mirrored on a second system. You might want to direct your inquiry to NetApp.

-- 
Daniel A. Morgan
http://www.psoug.org
damorgan_at_x.washington.edu
(replace x with u to respond)

Received on Wed Mar 22 2006 - 14:32:51 CST