BTRFS-RESCUE(8) Btrfs Manual BTRFS-RESCUE(8)
NAME
btrfs-rescue - Recover a damaged btrfs filesystem
SYNOPSIS
btrfs rescue <subcommand> <args>
DESCRIPTION
btrfs rescue is used to try to recover a damaged btrfs filesystem.
SUBCOMMAND
chunk-recover [options] <device>
Recover the chunk tree by scanning the devices
Options
-y
assume an answer of yes to all questions.
-v
verbose mode.
-h
help.
Note
Since chunk-recover will scan the whole device, it will be VERY slow especially executed on a large
device.
super-recover [options] <device>
Recover bad superblocks from good copies.
Options
-y
assume an answer of yes to all questions.
-v
verbose mode.
zero-log <device>
clear the filesystem log tree
This command will clear the filesystem log tree. This may fix a specific set of problem when the filesystem
mount fails due to the log replay. See below for sample stacktraces that may show up in system log.
The common case where this happens has been fixed a long time ago, so it is unlikely that you will see this
particular problem, but the utility is kept around.
Note
clearing the log may lead to loss of changes that were made since the last transaction commit. This may be
up to 30 seconds (default commit period) or less if the commit was implied by other filesystem activity.
One can determine whether zero-log is needed according to the kernel backtrace:
? replay_one_dir_item+0xb5/0xb5 [btrfs]
? walk_log_tree+0x9c/0x19d [btrfs]
AVAILABILITY
btrfs is part of btrfs-progs. Please refer to the btrfs wiki http://btrfs.wiki.kernel.org for further details.
SEE ALSO
mkfs.btrfs(8), btrfs-scrub(8), btrfs-check(8)
Btrfs v4.4.1 11/05/2016 BTRFS-RESCUE(8)
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