From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gitanes.rtfm.co.hu ([80.249.171.82]:59641 "EHLO gitanes.rtfm.co.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755764Ab3FCL4O (ORCPT ); Mon, 3 Jun 2013 07:56:14 -0400 Message-ID: <51AC845A.6000600@martos.bme.hu> Date: Mon, 03 Jun 2013 13:56:10 +0200 From: Papp Tamas MIME-Version: 1.0 To: Stefan Behrens CC: Josef Bacik , "linux-btrfs@vger.kernel.org" Subject: Re: oops at mount References: <51A73532.6060900@martos.bme.hu> <20130530123235.GA9829@localhost.localdomain> <51A74C5E.4030201@giantdisaster.de> In-Reply-To: <51A74C5E.4030201@giantdisaster.de> Content-Type: text/plain; charset=UTF-8; format=flowed Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 05/30/2013 02:55 PM, Stefan Behrens wrote: > > On Thu, 30 May 2013 08:32:35 -0400, Josef Bacik wrote: >> On Thu, May 30, 2013 at 05:17:06AM -0600, Papp Tamas wrote: >>> hi All, >>> >>> I'm new on the list. >>> >>> System: >>> Distributor ID: Ubuntu >>> Description: Ubuntu 13.04 >>> Release: 13.04 >>> Codename: raring >>> >>> Linux ctu 3.8.0-19-generic #30-Ubuntu SMP Wed May 1 16:35:23 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux >>> >>> The symptom is the same with Saucy 3.9 kernel. >> >> Can you try btrfs-next >> >> git://git.kernel.org/pub/scm/linux/kernel/git/josef/btrfs-next.git >> >> if it's still not fixed please file a bug at bugzilla.kernel.org and make sure >> the component is set to btrfs. Thanks, > > Papp is using an Intel X18-M/X25-M/X25-V G2 SSD. At least with an Intel > X25 SSD that identifies itself with "INTEL SSDSA2M080" and on one with > the ID "INTEL SSDSA2M040", I've tested whether they honor the flush > request. And these two SSDs don't do so, they ignore it. If you cut the > power after a flush request completes, the data that was written before > the flush request is gone, the write cache was _not_ flushed. > > You can only disable the write cache during/after every boot "hdparm -W > 0 /dev/sd..." (which reduces the SSDs write speed to about 4 MB/s), or > avoid such SSDs, or prepare to restore from backup occasionally. Basically it means it's not safe to use this SSD? I used it for 2 years with ext4 without any issue, before I switched to btrfs (on the root partition). In the meantime btrfs also was quite stable on my /data partition. After I reinstalled thr system with btrfs, this issue happened two times. But anyway, I thought cow should be able to handle these kind of issues by design. Am I wrong? Thanks, tamas