JFS, or Journaled File System, 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 File System 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.

Many successor file systems, Such as NTFS and Ext3, include a journal. JFS is reputed for consuming very little CPU-time.

Filesystem List

Filesystems: FAT | FATX | FAT12 | FAT16 | FATX16 | FAT32 | FATX32 | NTFS | JFS | Ext | Ext2 | Ext3 | HPFS | ReiserFS | Reiser4 | HFS+ | FFS | UFS1 | UFS2 | UFSMacOSX | XFS | OFS | BFS | BeFS | OpenBFS | NSS | NWFS | ODS5 | VxFS | ZFS | MFS | IFS | AFS | TVFS | MinixFS | SkyFS | AtheOSFS | ArlaFS | CDFS | UDF | CFS | DFS | OpenAFS | GFS | DTFS | CODA | UMSDOS | OldBeFS | RFS | EFS