06.09.03
Journaling almost rocks
People seem to think that Journaling is some sort of data saviour. But the truth that journaling will never do anything to keep files from being internally corrupted.
The only thing Journaling does is makes sure that the file system integrity is kept: That sectors are properly tied to files and that the files start and end at the place that the ‘table of contents’ says they will.
Whether an application will be able to recover the file is a completely different issue, and has really only been handled properly by RDBMS’s that have fully ACID (Atomic, Consistent, Isolation, Durable) transactions.
[Warning: Really bad mixed metaphor ahead!]
Journaling will keep your peanut butter cookies away from your chocolate ship cookies, but that doesn’t keep your cookies from coming out half-baked.
(Scary thought: Is this a reason why ‘longhorn’ will have a database-based file system? That would mean that the file system could ‘roll-back’ changes to a file when there’s a problem.)