Date: Thu, 13 Aug 2009 23:17:39 +0200
From: Emmanuel Florac <eflorac@intellique.com>
To: John Quigley <jquigley@jquigley.com>
Cc: XFS Development <xfs@oss.sgi.com>
Subject: Re: XFS corruption with failover
Message-ID: <20090813231739.5c7db91d@galadriel.home>
In-Reply-To: <4A8474D2.7050508@jquigley.com>
References: <4A8474D2.7050508@jquigley.com>
Organization: Intellique
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Le Thu, 13 Aug 2009 15:17:22 -0500 vous =E9criviez:

> Any advice or insight into what we're doing wrong would be very much
> appreciated.  My apologies in advance for the somewhat off-topic
> question.

By killing abruptly the primary server while doing IO, you're probably
pushing the envelope... You may have a somewhat better luck with a
cluster fs, OCFS2 works very well for me usually (GFS is a complete
PITA to setup).=20

The better option would be to disallow completely write
caching on the client side (because this is probably where it's going
wrong) however I don't know how. You can get it to flush extremely
often by playing with  /proc/sys/vm/dirty_expire_centiseconds
and /proc/sys/vm/dirty_writeback_centisecs, though. Safer settings
generally imply terrible performance, though, you've been warned.

Ah another thing may be some cache option in the iSCSI target. what
target are you using? =20

--=20
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Emmanuel Florac               www.intellique.com  =20
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