From: Jan Kara <jack@suse.cz>
To: Nikola Ciprich <nikola.ciprich@linuxbox.cz>
Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: BUG: enabling psacct breaks fsfreeze
Date: Wed, 31 Oct 2012 13:15:17 +0100 [thread overview]
Message-ID: <20121031121517.GD18424@quack.suse.cz> (raw)
In-Reply-To: <20121023094351.GC27919@pcnci.linuxbox.cz>
Hello,
On Tue 23-10-12 11:43:51, Nikola Ciprich wrote:
> while trying to create consistent backups of KVM guest, I've discovered
> that fsfreeze always hangs.. deeper investigation revealed psacct to be the culprit.
> When psacct is disabled, fsfreeze works fine, when enabled, the command never returns.
> I suppose that the problem is /var is not on separate partition (ie it's same volume
> as /) and psacct isn't able to dump process exit information about fsfreeze command
> thus creating deadlock..
> problem is 100% reproducible on both latest 3.0.x kernel and 3.7-r1c.
>
> Should more debugging information be needed, I'll be glad to provide whatever I can..
Thanks for report. Hum, I'm not sure how the deadlock can happen because
AFAIU audit sends a message via netlink to userspace and whatever audit
daemon does with it is its private thing. Can you please run:
echo w >/proc/sysrq-trigger
after the machine deadlocks and then take dmesg and attach it here? You'll
have to have the shell prepared and use serial console / netconsole to gather
dmesg or try your luck with copying via ssh / netcat.
Honza
--
Jan Kara <jack@suse.cz>
SUSE Labs, CR
next prev parent reply other threads:[~2012-10-31 12:15 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-23 9:43 BUG: enabling psacct breaks fsfreeze Nikola Ciprich
2012-10-31 12:15 ` Jan Kara [this message]
2012-10-31 12:46 ` Nikola Ciprich
2012-11-01 9:37 ` Jan Kara
2012-11-01 11:19 ` Jan Kara
2012-11-01 14:23 ` Nikola Ciprich
2012-11-01 22:50 ` Jan Kara
2012-11-02 9:50 ` Marco Stornelli
2012-11-02 10:40 ` Nikola Ciprich
2012-11-03 8:22 ` Marco Stornelli
2012-11-07 18:51 ` Jan Kara
2012-11-07 21:21 ` Nikola Ciprich
2012-11-07 22:32 ` Jan Kara
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