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,
missing codepage or helper program, or other error
In some cases useful info is found in syslog - try
dmesg | tail or 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 uuid: c2384ce9-bd38-480d-8b3b-fca6bd7921ac
Total devices 1 FS bytes used 82.52GB
devid 1 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@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
