Distributed Replicated Block Device (DRBD) development
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From: Lars Ellenberg <lars@linbit.com>
To: bugzilla-daemon@bugzilla.kernel.org
Cc: drbd-dev@lists.linbit.com
Subject: Re: [Drbd-dev] [Bug 41602] DRBD: possible deadlock in Ahead mode
Date: Wed, 24 Aug 2011 18:03:18 +0200	[thread overview]
Message-ID: <20110824160318.GF14479@barkeeper1-xen.linbit> (raw)
In-Reply-To: <201108241514.p7OFEliA003245@demeter2.kernel.org>

On Wed, Aug 24, 2011 at 03:14:47PM +0000, bugzilla-daemon@bugzilla.kernel.org wrote:
> https://bugzilla.kernel.org/show_bug.cgi?id=41602

> --- Comment #2 from Cyril B. <cbay@excellency.fr>  2011-08-24 15:14:47 ---
> I can't rule out a misconfiguration, but I've been using DRBD since 8.0 on many
> servers and I've never seen such a thing happen. It's only happened very
> recently since I began using Linux 3.0 on a few servers, a few days ago.
> 
> Even if it's a temporary network failure that I've never had before:
> 
>  - how comes even a drbdadm disconnect doesn't work (i.e. hangs), and I have to
> reboot the primary server to be able to write on my filesystem again?

Arguably a design bug, the default disconnect waits for all current
requests to be handled.

You can try to --force disconnect, though.

>  - isn't the Ahead mode supposed to not block IO if the buffer is full and/or
> the secondary server is not accessible?

Well, yes, but it still needs to send some bytes (as oposed to the full
data block) to the peer. And if sendmsg blocks/times out/makes no
progress for whatever reason, we cannot do anything about that.

-- 
: Lars Ellenberg
: LINBIT | Your Way to High Availability
: DRBD/HA support and consulting http://www.linbit.com

DRBD® and LINBIT® are registered trademarks of LINBIT, Austria.

           reply	other threads:[~2011-08-24 16:34 UTC|newest]

Thread overview: expand[flat|nested]  mbox.gz  Atom feed
 [parent not found: <201108241514.p7OFEliA003245@demeter2.kernel.org>]

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