fedora-list digest, Vol 1 #374 - 25 msgs

[Robert O'Connor]

If this is production consider a configuration with a hot spare and 
always keep a spare disk available on the shelf. If one fails from a 
batch another cannot be far behind (remember Murphy).

Bob

Robert O'Connor
AIS Infrastructure
Penn State University

On Nov 26, 2003, at 11:12 AM, fedora-list-request at redhat.com wrote:

> To: fedora-list at redhat.com
> Subject: Re: RSYNC Fedora
> From: "Edward C. Bailey" <ed at redhat.com>
> Date: Wed, 26 Nov 2003 10:59:40 -0500
> Reply-To: fedora-list at redhat.com
>
>>>>>> "Brian" == Brian Fahrlander <Brian at Fahrlander.net> writes:
>
> Brian>     I once asked a woman that worked at Veritas in tech support.
> Brian> She said that on all these RAID arrays, loss of a second disk is
> Brian> _ALWAYS_ fatal.  I was stunned.
>
> Yup, she was right.
>
> Brian>     I mean, a 30 drive array...and if the second drive goes 
> out, the
> Brian> entire thing is toast?
>
> If you choose to set up a single array with 30 drives in it, that is 
> correct.
>
> Brian>     There gets to be a point where this is a problem.  In 1-5 
> disk
> Brian> arrays, what are the chances of a second drive going out? Right:
> Brian> almost nil.
>
> Brian>     But when you have 50 drives in a special bay, the chances 
> of a
> Brian> second drive going out while you locate a vendor, find out it's 
> been
> Brian> obsoleted since it was installed, order a new part....
>
> Exactly, so as the old joke goes when the guy tells his doctor it hurts
> when he moves his arm, then don't do that! :-)
>
> Instead, keep the number of drives in any given array low.  If you need
> more space, look at getting bigger drives.  If you need even more 
> space,
> consider "stacking" arrays (make a RAID 0 array out of as many 3-drive 
> RAID
> 5 arrays as you need to reach your storage requirements, for example). 
>  By
> doing this you still are exposed to the risk of multiple drives 
> failing at
> any given time, but you reduce the exposure of any one array losing 
> more
> than one drive.
>
>                                 Ed
> -- 
> Ed Bailey        Red Hat, Inc.          http://www.redhat.com/