From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Sebastian 'gonX' Jensen" Subject: Re: Another checksum error bugreport Date: Wed, 29 Sep 2010 13:37:19 +0200 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Cc: linux-btrfs To: Francis Galiegue Return-path: In-Reply-To: List-ID: On 29 September 2010 13:12, Francis Galiegue wrot= e: > On Wed, Sep 29, 2010 at 12:48, Sebastian 'gonX' Jensen > wrote: >> Hey guys, >> >> Today I experienced my first checksum error just out of the blue - a= nd >> it's not just the 'csum + 1 =3D private' issue, it's a completely >> different one. Because of this, I am unable to retrieve the data off >> the drive, even with nodatasum enabled - I simply get an I/O error. >> Here's the dmesg output: >> >> [149423.845177] btrfs: setting nodatasum >> [149423.850339] Btrfs detected SSD devices, enabling SSD mode >> [149432.094728] btrfs csum failed ino 259 off 26701824 csum 38758670= 41 >> private 371726550 >> [149432.117938] btrfs csum failed ino 259 off 26701824 csum 38758670= 41 >> private 371726550 >> [149432.118340] btrfs csum failed ino 259 off 26701824 csum 38758670= 41 >> private 371726550 >> [149432.125671] btrfs csum failed ino 259 off 26701824 csum 38758670= 41 >> private 371726550 >> [149432.126075] btrfs csum failed ino 259 off 26701824 csum 38758670= 41 >> private 371726550 >> [149432.135671] btrfs csum failed ino 259 off 26701824 csum 38758670= 41 >> private 371726550 >> >> I would really like to have the files on the drive retrieved in thei= r >> entirety, but if that is not possible then that is also OK. Consider >> this a bugreport and a question on how to retrieve the data now. >> > > Which kernel is that? It was one of the 2.6.35 versions from the Ubuntu repository. I'm running Ubuntu 10.04 Server. > A patch made it in 2.6.36-rc6 which fixed an important bug in the bdi > code, wherein write requests and discard requests were merged, > transforming all requests in discard requests. > > And you use an SSD... Hmmm. > > -- > Francis Galiegue, fgaliegue@gmail.com > "It seems obvious [...] that at least some 'business intelligence' > tools invest so much intelligence on the business side that they have > nothing left for generating SQL queries" (St=C3=A9phane Faroult, in "= The > Art of SQL", ISBN 0-596-00894-5) > Well, overall it seems to work now. I downgraded to the .32 version in the Ubuntu 10.04 repository and now I do not get any errors from dmesg. I don't know what caused it, but I think I'll stick to stable kernel versions instead. Since this is a production system it's not very easy for me to troubleshoot this any further if it requires a reboot. I can unmount and mount the drive from time to time, but not reboot. If you want btrfs-debug-tree output or something, let me know. Regards, Sebastian J. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" = in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html