Mounting a BTRFS filesystem fails with "wrong fs type, bad option, bad superblock on /dev/<devicename>"
This document (7018133) is provided subject to the disclaimer at the end of this document.
Environment
SUSE Linux Enterprise Server 12
SUSE Linux Enterprise Server 12 Service Pack 1 (SLES 12 SP1)
SUSE Linux Enterprise Server 12 Service Pack 1 (SLES 12 SP1)
Situation
Trying to mount a BTRFS filesystem returns the following error:
mount: wrong fs type, bad option, bad superblock on /dev/<devicename>, missing codepage or helper program, or other error In some cases useful info is found in syslog - try dmesg | tail or so
Resolution
Check with 'dmesg' if BTRFS related messages have been logged. If something like the following is shown:
Or a kernel stack trace, containing lines similar to the following:
It is likely due to a corrupted BTRFS log, to clear the log run either (depending on the SLES version):
Where <devicename> in the above examples is the device containing the problematic BTRFS filesystem.
BTRFS: failed to read log tree
Or a kernel stack trace, containing lines similar to the following:
replay_one_dir_item+0xb5/0xb5 [btrfs] walk_log_tree+0x9c/0x19d [btrfs] btrfs_read_fs_root_no_radix+0x169/0x1a1 [btrfs] btrfs_recover_log_trees+0x195/0x29c [btrfs] replay_one_dir_item+0xb5/0xb5 [btrfs]
It is likely due to a corrupted BTRFS log, to clear the log run either (depending on the SLES version):
orbtrfs-zero-log /dev/<devicename>
btrfs rescue zero-log /dev/<devicename>
Where <devicename> in the above examples is the device containing the problematic BTRFS filesystem.
Disclaimer
This Support Knowledgebase provides a valuable tool for SUSE customers and parties interested in our products and solutions to acquire information, ideas and learn from one another. Materials are provided for informational, personal or non-commercial use within your organization and are presented "AS IS" WITHOUT WARRANTY OF ANY KIND.
- Document ID:7018133
- Creation Date: 10-Oct-2016
- Modified Date:03-Mar-2020
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- SUSE Linux Enterprise Desktop
- SUSE Linux Enterprise Server
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