From: Bill Davidsen <davidsen@tmr.com>
To: John Rowe <rowe@excc.ex.ac.uk>
Cc: linux-raid@vger.kernel.org
Subject: Re: Two-disk RAID5?
Date: Thu, 04 May 2006 21:22:29 -0400 [thread overview]
Message-ID: <445AA8D5.2040604@tmr.com> (raw)
In-Reply-To: <1146069707.10253.50.camel@kenny>
John Rowe wrote:
>I'm about to create a RAID1 file system and a strange thought occurs to
>me: if I create a two-disk RAID5 array then I can grow it later by the
>simple expedient of adding a third disk and hence doubling its size.
>
>Is there any real down-side to this, such as performance? Alternatively
>is it likely that mdadm will soon be able to convert a RAID1 pair to
>RAID5 any time soon? (Just how different are they anyway? Isn't the
>RAID4/5 checksum just an OR?)
>
I think it works, I just set up a little test case with two 20MB files
and loopback mount. The mdadm seems to work, the mke2fs seems to work,
the f/s is there. Please verify, this system is a bit (okay a bunch) hacked.
--
bill davidsen <davidsen@tmr.com>
CTO TMR Associates, Inc
Doing interesting things with small computers since 1979
next prev parent reply other threads:[~2006-05-05 1:22 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-04-26 16:41 Two-disk RAID5? John Rowe
2006-04-26 17:18 ` Jon Lewis
2006-04-26 18:46 ` Tuomas Leikola
2006-05-05 1:22 ` Bill Davidsen [this message]
-- strict thread matches above, loose matches on Subject: below --
2006-04-26 18:58 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
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