[3068] in SIPB-AFS-requests
Re: FY98 budgeting and AFS
daemon@ATHENA.MIT.EDU (Richard Basch)
Thu Jul 16 00:25:25 1998
Date: Wed, 15 Jul 1998 13:50:58 -0400
To: Greg Hudson <ghudson@MIT.EDU>
Cc: sipb-machine-room@MIT.EDU, sipb-afsreq@MIT.EDU
In-Reply-To: <199807151729.NAA04114@small-gods.mit.edu>
From: "Richard Basch" <basch@lehman.com>
On Wed, 15-July-1998, "Greg Hudson" wrote to "sipb-machine-room@MIT.EDU, sipb-afsreq@MIT.EDU" saying:
> I mainly want to talk about AFS right now. ASO has recently qualified
> some 72GB Box Hill RAID units, which cost about $23,000 apiece. I
> think it would make our cell easier to manage if we started to
> transition to these units instead of maintaining a plethora of small,
> differently-sized disks. And, of course, RAID units would make the
> cell a lot more reliable.
. . .
> So I would like to:
>
> * Get opinions from AFS maintainers about buying RAID units.
> Does anyone think it's a bad idea? Do we want to restrict
> ourselves to only one of them this year (even if we don't
> have to for financial reasons) because they're new?
From personal experience with several RAID vendors, including Clariion,
Conley, and Boxhill, I am less than impressed with RAID technology. At
Lehman, our high-availability services have suffered primarily for two
reasons:
- RAID failures
- HA software failures
RAID units are generally a little less manageable, have some
single-points-of-failure (ie. cache battery, single write-through cache
path, ...)
We are still a heavy RAID user, but I strongly suggest you ask
yourselves what you expect to be solving. Are there frequent drive
failures that you need to protect against? Will you be using the RAID
management facilities often enough to quickly restore RAID sets in the
event of a failure (or will you be spending more time investigating the
solution)? Or, are you limited by throughput, and require the striping
that RAID provides?
These are merely questions to ponder... but before you invest in RAID,
can you provide details about the problems that led you to pursue RAID?
--
Richard Basch
AVP, Technology Integration URL: http://web.mit.edu/basch/www/home.html
Lehman Brothers, Inc. Email: basch@lehman.com, basch@mit.edu
101 Hudson St., 28th Floor Voice: +1 201 524 5049
Jersey City, NJ 07302-3988 Fax: +1 201 524 2111
