[Drbd-dev] DRBD8: drbd nodes deadlock in WFBitMapT

[Montrose, Ernest]

Phil,
I will try that patch and let you know but first attached is the logs
for drbd2 for both Ben and Jerry.  For over a week I tried to figure out
how we got into that state but failed.  So thanks for the help.  I
flagged some weirdness where there appear to be missing lines.  I
suspect that this may have to do with the way we collect these logs
here.  The problem is near the bottom of the logs since we stop the
tests as soon as we notice the deadlock. Bear in mind that the test is
to power cycle the nodes and see what happens to various subsystems.

And...O! sorry you're not going to be on the East coast we would have
been thrilled to meet you!

Thanks,
EM--

-----Original Message-----
From: Philipp Reisner [mailto:philipp.reisner at linbit.com] 
Sent: Tuesday, April 03, 2007 5:35 AM
To: drbd-dev at linbit.com
Cc: Montrose, Ernest
Subject: Re: [Drbd-dev] DRBD8: drbd nodes deadlock in WFBitMapT

Am Montag, 2. April 2007 23:44 schrieb Montrose, Ernest:
> Phil,
> OK...I have learned a tad more since that last email.  So before I
even
> try the proposed patch here is a way I was able to duplicate the
> problem.
> Perhaps that will help a bit.  Here it is with two nodes 'a' and 'b' .
> Suppose
> They are in steady states with UUIDS:
> Xa:0:Ha:HH:1:1:0:1:0:0
> Xb:0:Hb:HH:1:1:0:1:0:0
> Role Secondary/Secondary
>
> 1) Disconnect/detach /dev/drbdX on nodea
> 2) Move Current UUID of nodea to history-UUID of nodea and set
> current_UUID of nodea to 00000000000 with drbdmeta..
> 0:0:Xa:HH:1:1:0:1:0:0
> 3) Now attach and connect /dev/drbdX and the problem will occur
>
> I have attached the logs for my "manufactured" version of the problem
>

Ernest,

You are right, that DRBD should get out of this situation. The attached
patch fixes this. (I will commit it when you confirm that it also fixes
the issue for your)

But I am still asking myself how the CRASHED_PRIMARY got lost. Ernest,
do you still have the log of jerry from Mar 23 13:16:54 ?

I would really like to see the last 30 lines before Mar 23 13:16:54.

Thanks!
-Phil
-- 
: Dipl-Ing Philipp Reisner                      Tel +43-1-8178292-50 :
: LINBIT Information Technologies GmbH          Fax +43-1-8178292-82 :
: Vivenotgasse 48, 1120 Vienna, Austria        http://www.linbit.com :
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