Return to BSD News archive
Path: euryale.cc.adfa.oz.au!newshost.carno.net.au!harbinger.cc.monash.edu.au!munnari.OZ.AU!news.ecn.uoknor.edu!news.wildstar.net!news.ececs.uc.edu!news.kei.com!newsfeed.internetmci.com!news.sprintlink.net!news-peer.sprintlink.net!news.mathworks.com!uunet!news-in2.uu.net!news.artisoft.com!usenet
From: Terry Lambert <terry@lambert.org>
Newsgroups: comp.unix.bsd.freebsd.misc
Subject: Re: RAID sw?
Date: Mon, 30 Sep 1996 12:00:35 -0700
Organization: Me
Lines: 43
Message-ID: <325018D3.1131EC4C@lambert.org>
References: <chad-3009960810030001@sverige.pengar.com>
NNTP-Posting-Host: hecate.artisoft.com
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Mailer: Mozilla 2.01 (X11; I; Linux 1.1.76 i486)
Chad Leigh wrote:
] I am wanting to setup a FreeBSD system to handle large amounts
] of email. If possible I would like to have a raid stripe set
] (with parity? -- the one where a disk failure can be recovered
] from). Is RAID (any level) supported on FreeBSD? Are there
] any commercial implementations?
]
] I would probably be using 2940 SCSI adapters.
RAID calculation in software is extremely expensive, especially
for the hamming codes. It is so expensive that no one has really
bothered to implement code to do it.
Typically, your best bet would be a RAID-capable controller.
Unfortunately, the Adaptec 3940, a RAID-capable controller, does
not have sufficient information published about it to be able to
support it as anything other than a dumb 2940.
I would suggest CCD for striping, mirroring, and volume spanning,
but your recoverability requirements imply a RAID 5 requirement.
There is a Compaq RAID SCSI controller for which a third party
person has written a driver. It appears to work fine, but since
the driver isn't in the kernel by default, you will have to contact
him directly for a boot/install disk.
You can find him in www.dejanews.com's search engine -- look for
"bsd compaq raid" or something similar, since he posted about the
driver to this group (about a year or so ago).
For what it's worth, I believe you'd be pretty unhappy with a
software raid soloution in any case -- the performance would
*have* to be pretty terrible.
Terry Lambert
terry@lambert.org
---
Any opinions in this posting are my own and not those of my present
or previous employers.