* Re: [Drbd-dev] [Bug 41602] DRBD: possible deadlock in Ahead mode
[not found] ` <201108241514.p7OFEliA003245@demeter2.kernel.org>
@ 2011-08-24 16:03 ` Lars Ellenberg
0 siblings, 0 replies; only message in thread
From: Lars Ellenberg @ 2011-08-24 16:03 UTC (permalink / raw)
To: bugzilla-daemon; +Cc: drbd-dev
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.
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