A file system in which the
hard disk maintains data integrity in the event of a system
crash or if the system is otherwise halted abnormally. The journaled file system (JFS) maintains a log, or journal, of what activity has taken place in the main data areas of the disk; if a crash occurs, any lost data can be recreated because updates to the
metadata in
directories and
bit maps have been written to a serial log. The JFS not only returns the data to the pre-crash configuration but also recovers unsaved data and stores it in the location it would have been stored in if the system had not been unexpectedly interrupted.
