A journaling filesystem is a filesystem that maintains a special file called a journal that is used to REPAIR any inconsistencies that occur as the result of an improper shutdown of a computer.

In journaling file systems, every time GFS2 writes metadata, the metadata is committed to the journal before it is put into place. 

This ensures that if the SYSTEM crashes or loses POWER, you will recover all of the metadata when the journal is automatically replayed at mount time.

GFS2 requires one journal for each NODE in the cluster that needs to mount the file system. For example, if you have a 16-node cluster but NEED to mount only the file system from two nodes, you need only two journals. If you need to mount from a third node, you can always add a journal with the gfs2_jadd command.

A journaling filesystem is a filesystem that maintains a special file called a journal that is used to repair any inconsistencies that occur as the result of an improper shutdown of a computer.

In journaling file systems, every time GFS2 writes metadata, the metadata is committed to the journal before it is put into place. 

This ensures that if the system crashes or loses power, you will recover all of the metadata when the journal is automatically replayed at mount time.

GFS2 requires one journal for each node in the cluster that needs to mount the file system. For example, if you have a 16-node cluster but need to mount only the file system from two nodes, you need only two journals. If you need to mount from a third node, you can always add a journal with the gfs2_jadd command.