The EXT4 file-system today deprecated its journaled mode of the "data=journal" mount option. Following its deprecation, this mode is planned for removal in the year 2028.

The data=journal mode for EXT4 is where all file data and metadata is written to the file-system's journal before being committed to the main file-system. In the event of a crash or power loss, the journal can then be replayed to recover the data.

The EXT4 data=journal mode is great for those very concerned about data integrity and safety but comes with significant hits to the write performance compared to the default ordered (data=ordered) mode or data=writeback. Using the journaled mode also disables delayed allocation and Direct I/O support.

Per today's Git merge for Linux 7.3, the EXT4 data=journal feature is deprecated and support for it will be removed in early 2028 following the 2027 Linux LTS kernel version.