From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gregory L Shomo Subject: parent transid troubles Date: Tue, 19 Apr 2011 15:08:13 -0400 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii To: linux-btrfs@vger.kernel.org Return-path: List-ID: Hello list- Under heavy load (i/o), one of our fileservers lost two drives in a raid6 configuration. After the drives were synchronized, we can no longer mount the multiple-device btrfs filesystem due to (at least) parent transid verification. btrfsck built from git commit 1b444cd2e6ab8dcafdd47dbaeaae369dd1517c17 runs for a while and then aborts on 'failed to find block number'. Sample output includes : parent transid verify failed on 22569952096256 wanted 176066 found 176064 parent transid verify failed on 22569952096256 wanted 176066 found 176064 parent transid verify failed on 20403515183104 wanted 176066 found 174710 parent transid verify failed on 20403515183104 wanted 176066 found 174710 parent transid verify failed on 1265784008704 wanted 176066 found 175341 !-- snip bad block 1099696562176 leaf parent key incorrect 1117248647168 !-- snip Extent back ref already exists for 1130294538240 parent 0 root 2 Extent back ref already exists for 1130295001088 parent 0 root 2 !-- snip fs uuid d8464857-db87-412e-9d57-ece6c2054f40 chunk uuid 52a652a3-650d-4dd7-aaa2-6f096a714bbf item 0 key (20407857930240 EXTENT_ITEM 4096) itemoff 3944 itemsize 51 extent refs 1 gen 165193 flags 2 tree block key (257306671 1 0) level 0 tree block backref root 5 item 1 key (20407857934336 EXTENT_ITEM 4096) itemoff 3893 itemsize 51 extent refs 1 gen 165308 flags 2 tree block key (257585950 1 0) level 0 tree block backref root 5 !-- snip failed to find block number 20407858008064 Aborted Output is exactly the same when run against both devices, even when using 'btrfsck -s1'. Should we light a candle and say 'goodbye' to the data or is there some hope that btrfsck will be able to help us mount the filesystem ? Is there any additional information that is useful to the developers ? The system is based on fedora-14, btrfs-progs-0.19-12.fc14.x86_64, and the arcmsr module (built from the 1.20.0X.15-100729 sources). - greg