XFS Repair
The xfs_repair command is a powerful utility used to
repair a corrupted XFS filesystem. Filesystem corruption can occur
due to various reasons, including unexpected shutdowns, hardware
failures, or software bugs. Using xfs_repair is often a
last resort to restore the integrity of your XFS filesystem and
recover lost data.
Basic XFS Filesystem Repair
To perform a standard repair on an XFS filesystem, you can use the
following command. It's crucial to unmount the filesystem before
running xfs_repair to prevent further data loss or
corruption.
# repair an XFS filesystem
xfs_repair /dev/dm-0Forcing Log Zeroing (Last Resort)
In severe cases of corruption, the filesystem log might be in an
inconsistent state. The -L option forces the log to be
zeroed, which can help in repairing the filesystem but may lead to
data loss. Use this option with extreme caution.
The -v option provides verbose output, which can be
helpful for diagnosing issues.
# last resort option:
# -L: Force Log Zeroing. zero the log even if it is dirty (contains metadata
# changes). When using this option the filesystem will likely appear to be
# corrupt, and can cause the loss of user files and/or data.
xfs_repair -v -L /dev/dm-0Important Considerations Before Running xfs_repair
1. Backup Your Data
Before attempting any filesystem repair, it is highly recommended to
back up any critical data from the affected partition. While
xfs_repair aims to fix corruption, there's always a
risk of data loss, especially when using options like
-L.
2. Unmount the Filesystem
Never run xfs_repair on a mounted filesystem. Doing so
can lead to severe data corruption and system instability. Ensure
the filesystem is unmounted using the umount command.
sudo umount /dev/dm-03. Understand the Risks
xfs_repair modifies the filesystem's metadata. While
it's designed to fix errors, aggressive options can result in data
loss. Always proceed with caution and ensure you understand the
implications of each option.