From mboxrd@z Thu Jan 1 00:00:00 1970 From: Theodore Ts'o Subject: Re: ext4 unknown problem Date: Tue, 31 Jul 2012 12:34:33 -0400 Message-ID: <20120731163433.GA32228@thunk.org> References: <613523755.179491343719039762.JavaMail.root@shiva> <1343355595.179511343719122536.JavaMail.root@shiva> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-ext4@vger.kernel.org, info To: luvar@plaintext.sk Return-path: Received: from li9-11.members.linode.com ([67.18.176.11]:42296 "EHLO imap.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754493Ab2GaQej (ORCPT ); Tue, 31 Jul 2012 12:34:39 -0400 Content-Disposition: inline In-Reply-To: <1343355595.179511343719122536.JavaMail.root@shiva> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Tue, Jul 31, 2012 at 08:18:42AM +0100, luvar@plaintext.sk wrote: > usb 2-4.4: USB disconnect, device number 10 So what's this? Is this at all related to how you've created your RAID device? You haven't told us what your RAID device on dm-3 is composed of (i.e., what are the underlying devices). And there were no OOPS or BUG or WARN messages in your dmesg? > PS: Writing to disk from jbd2/dm-3-8 still active (iotop shows it still on top of I/O activity). I'm not sure if your kernel has trace debugging enabled, or if you have debugfs mounted, but try this: echo 1 > /sys/kernel/debug/tracing/events/jbd2/jbd2_run_stats/enable cat /sys/kernel/debug/tracing/trace_pipe If these commands don't work try running this command and see if it works then: mount -t debugfs debugfs /sys/kernel/debug Let us know if you see jbd2 activity. It's possible that sync isn't returning because some process is still writing to the file system, and if I recall correctly, Linux 3.2 didn't have some of the sync livelock fixes that could cause sync to not return until the file system had actually quieted down completely. Regards, - Ted