From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Switzer Subject: Recover Corruption - verify_parent_transid Date: Mon, 9 Aug 2010 21:43:05 -0500 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 To: linux-btrfs@vger.kernel.org Return-path: In-Reply-To: List-ID: I have a btrfs partition that is failing to mount and I was hoping I could recover it somehow. Mount returns immediately with a bad superblock error: mount: wrong fs type, bad option, bad superblock on /dev/sdb1, =A0=A0 =A0 =A0 missing codepage or helper program, or other error =A0=A0 =A0 =A0 In some cases useful info is found in syslog - try =A0=A0 =A0 =A0 dmesg | tail =A0or so Looking in the syslog, we see the following errors: [ 4328.614123] device fsid d4838bde94c38c2-ac2179bda6fc3b8b devid 1 transid 1133 /dev/sdb1 [ 4328.618807] parent transid verify failed on 117069225984 wanted 1133 found 812 [ 4328.619570] parent transid verify failed on 117069225984 wanted 1133 found 812 [ 4328.619928] parent transid verify failed on 117069225984 wanted 1133 found 812 [ 4328.621323] btrfs: open_ctree failed These are the same errors that btrfsck returns, which I learned in retrospect will not fix errors. Here is what btrfs-show returns: Label: none =A0uuid: c2384ce9-bd38-480d-8b3b-fca6bd7921ac Total devices 1 FS bytes used 82.52GB devid =A0 =A01 size 1.82TB used 112.04GB path /dev/sdb1 Btrfs Btrfs v0.19 This system is running the following kernel: $ uname -a Linux erebus 2.6.32-gentoo-r7 #7 Sun May 30 21:33:03 CDT 2010 i686 Pentium III (Coppermine) GenuineIntel GNU/Linux The system was busy copying files to the partition when it died due to a power failure. The partition/device was not renamed between reboots. The partition is a 2TB partition (big media drive), so if I have to lose the data associated with the errors, I'd be okay with that (rollback the transaction for that object or just remove the data outright). -Jason "s1n" Switzer -- 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