3 / 25 File Systems

Journaling and Crash Consistency

A file system write requires updating three structures: the data block, the inode, and the bitmap. The system crashes after writing only the inode. What problem does this cause, and what mechanism prevents it?

A

No problem; fsck runs at boot and fixes any inconsistencies automatically

B

Data corruption beyond recovery; RAID prevents this by mirroring writes

C

File system inconsistency; journaling prevents this by logging changes before committing them

D

The file is lost; the OS re-creates it from backup on next boot