Of course, if you have a journalling filesystem
such as ufs
(or even ntfs
becomes largely redundant.
Rather than having to check the entire filesystem in the event of an error, the filesystem is simply rebuilt by consulting the journal. As the journal is updated by the operating system before any change is committed to disk, the uncomitted changes made before the crash can be brought into sync, bringing the filesystem back to a coherent state much more quickly.
This is infinitely useful with a system with large numbers of drives.