6 btrfs-rescue - Recover a damaged btrfs filesystem
10 *btrfs rescue* <subcommand> <args>
14 *btrfs rescue* is used to try to recover a damaged btrfs filesystem.
18 *chunk-recover* [options] <device>::
19 Recover the chunk tree by scanning the devices
24 assume an answer of 'yes' to all questions.
30 NOTE: Since *chunk-recover* will scan the whole device, it will be *VERY* slow
31 especially executed on a large device.
33 *super-recover* [options] <device>::
34 Recover bad superblocks from good copies.
39 assume an answer of 'yes' to all questions.
46 *btrfs rescue zero-log* will remove the log tree if log tree is corrupt, which
47 will allow you to mount the filesystem again.
49 The common case where this happens has been fixed a long time ago,
50 so it is unlikely that you will see this particular problem.
52 One can determine whether *btrfs-zero-log* is needed according to the kernel
55 ? replay_one_dir_item+0xb5/0xb5 [btrfs]
56 ? walk_log_tree+0x9c/0x19d [btrfs]
57 ? btrfs_read_fs_root_no_radix+0x169/0x1a1 [btrfs]
58 ? btrfs_recover_log_trees+0x195/0x29c [btrfs]
59 ? replay_one_dir_item+0xb5/0xb5 [btrfs]
60 ? btree_read_extent_buffer_pages+0x76/0xbc [btrfs]
61 ? open_ctree+0xff6/0x132c [btrfs]
64 If the errors are like above, then *zero-log* could be used to clear
65 the log and the filesystem may be mounted normally again.
69 *btrfs rescue* returns a zero exit status if it succeeds. Non zero is
70 returned in case of failure.
74 *btrfs* is part of btrfs-progs.
75 Please refer to the btrfs wiki http://btrfs.wiki.kernel.org for