xfs_logprint

xfs_logprint [-acdghimnrstvV] [-b blksize] [-o offset] log

-a
    Print all log records. By default, only log records pertaining to metadata updates are printed.

-b blksize
    Use blksize as the filesystem block size. If not specified, xfs_logprint attempts to determine the block size automatically.

-c
    Disable log compression.

-d
    Print debug information to stderr.

-g
    Print the GUID of the filesystem. GUID is also known as the filesystem UUID

-h
    Print a help message, then exit.

-i
    Print inode information for all inodes that appear in the log.

-m
    Print summary information for each log record.

-n
    Do not print any output; only perform syntax checking.

-o offset
    Start reading the log at the specified offset in bytes.

-r
    Recover log contents. This option is useful for recovering data from a corrupted log.

-s
    Print superblock information.

-t
    Print transaction header information for each log record.

-v
    Be verbose. Print more detailed information.

-V
    Print the version number and exit.

log
    The path to the XFS log device or image file.

The xfs_logprint command is a diagnostic tool used to read and interpret the internal log records of an XFS filesystem. This utility allows system administrators and developers to examine the contents of the XFS transaction log, helping in debugging and troubleshooting filesystem issues, such as data corruption, unexpected behavior, or performance bottlenecks.

By analyzing the log data, it's possible to track the sequence of operations performed on the filesystem, identify potential inconsistencies, and understand the context surrounding errors. Understanding the transactions that occur in the log may provide important insights for recovering from file system failures. The output is typically formatted for human readability, making it easier to discern the different types of log records and their associated data. The logs are read from the raw disk device or image files.

Interpreting the output of xfs_logprint requires a deep understanding of the XFS filesystem internals. The output format and contents can vary depending on the XFS version and configuration.

The xfs_logprint command returns 0 on success. A non-zero exit status indicates an error, such as an invalid argument, failure to open the log file, or corruption in the log data.

The xfs_logprint command can reveal sensitive information about the filesystem, including data modifications and file metadata. Restrict access to the log file to authorized users only.

The xfs_logprint command has been part of the XFS filesystem utilities since its early development. It evolved alongside the XFS filesystem itself, adapting to changes in the log structure and functionality. It's primarily used by filesystem developers and administrators for debugging and forensic analysis.

xfs(5), xfs_repair(8), xfsdump(8)