From: Erik Mouw <erik@harddisk-recovery.com>
To: Bill Davidsen <davidsen@tmr.com>
Cc: Jon Lewis <jlewis@lewis.org>,
"Jansen, Frank" <fjansen@egenera.com>,
Tuomas Leikola <tuomas.leikola@gmail.com>,
John Rowe <rowe@excc.ex.ac.uk>,
linux-raid@vger.kernel.org
Subject: Re: Two-disk RAID5?
Date: Fri, 5 May 2006 12:24:05 +0200 [thread overview]
Message-ID: <20060505102405.GA4900@harddisk-recovery.com> (raw)
In-Reply-To: <445AA801.6050404@tmr.com>
On Thu, May 04, 2006 at 09:18:57PM -0400, Bill Davidsen wrote:
> Erik Mouw wrote:
> >No, the other way around: RAID1 is a special case of RAID5.
> >
> No it isn't. If you have N drives in RAID1 you have N independent copies
> of the data and no parity, there's just no corresponding thing in RAID5,
> which has one copy of the data, plus parity. There is no special case,
> it just doesn't work that way. Set N>2 and report back.
Just write out the formulas and it becomes obvious.
> Sorry, I couldn't find a diplomatic way to say you're completely wrong.
I guess we have to agree to disagree.
Erik
--
+-- Erik Mouw -- www.harddisk-recovery.com -- +31 70 370 12 90 --
| Lab address: Delftechpark 26, 2628 XH, Delft, The Netherlands
next prev parent reply other threads:[~2006-05-05 10:24 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-04-26 18:58 Two-disk RAID5? Jansen, Frank
2006-04-26 19:22 ` Jon Lewis
2006-04-26 22:53 ` Neil Brown
2006-04-27 4:15 ` Al Boldi
2006-05-01 17:11 ` Erik Mouw
2006-05-05 1:18 ` Bill Davidsen
2006-05-05 9:31 ` John Rowe
2006-05-05 10:03 ` Neil Brown
2006-05-05 10:24 ` Erik Mouw [this message]
-- strict thread matches above, loose matches on Subject: below --
2006-04-26 16:41 John Rowe
2006-04-26 17:18 ` Jon Lewis
2006-04-26 18:46 ` Tuomas Leikola
2006-05-05 1:22 ` Bill Davidsen
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