From: Miles Fidelman <mfidelman@meetinghouse.net>
Cc: linux-raid@vger.kernel.org
Subject: Re: possibly silly question (raid failover)
Date: Tue, 01 Nov 2011 09:05:25 -0400 [thread overview]
Message-ID: <4EAFEE95.6070608@meetinghouse.net> (raw)
In-Reply-To: <j8odkj$46h$1@dough.gmane.org>
David Brown wrote:
>
> One thing to watch out for when making high-availability systems and
> using RAID1 (or RAID10), is that RAID1 only tolerates a single failure
> in the worst case. If you have built your disk image spread across
> different machines with two-copy RAID1, and a server goes down, then
> the rest then becomes vulnerable to a single disk failure (or a single
> unrecoverable read error).
>
> It's a different matter if you are building a 4-way mirror from the
> four servers, of course.
>
Just a nit here: I'm looking at "md RAID10" which behaves quite
differently that conventional RAID10. Rather than striping and raiding
as separate operations, it does both as a unitary operation -
essentially spreading n copies of each block across m disks. Rather
clever that way.
Hence my thought about a 16-disk md RAID10 array - which offers lots of
redundancy.
Miles
--
In theory, there is no difference between theory and practice.
In<fnord> practice, there is. .... Yogi Berra
next prev parent reply other threads:[~2011-11-01 13:05 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-11-01 0:38 possibly silly question (raid failover) Miles Fidelman
2011-11-01 9:14 ` David Brown
2011-11-01 13:05 ` Miles Fidelman [this message]
2011-11-01 13:37 ` John Robinson
2011-11-01 14:36 ` David Brown
2011-11-01 20:13 ` Miles Fidelman
2011-11-01 21:20 ` Robin Hill
2011-11-01 21:32 ` Miles Fidelman
2011-11-01 21:50 ` Robin Hill
2011-11-01 22:35 ` Miles Fidelman
2011-11-01 22:00 ` David Brown
2011-11-01 22:58 ` Miles Fidelman
2011-11-02 10:36 ` David Brown
2011-11-01 22:15 ` keld
2011-11-01 22:25 ` NeilBrown
2011-11-01 22:38 ` Miles Fidelman
2011-11-02 1:40 ` keld
2011-11-02 1:37 ` keld
2011-11-02 1:48 ` NeilBrown
2011-11-02 7:02 ` keld
2011-11-02 9:20 ` Jonathan Tripathy
2011-11-02 11:27 ` David Brown
2011-11-01 9:26 ` Johannes Truschnigg
2011-11-01 13:02 ` Miles Fidelman
2011-11-01 13:33 ` John Robinson
2011-11-02 6:41 ` Stan Hoeppner
2011-11-02 13:17 ` Miles Fidelman
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