Jump to content

Log-structured filesystem

From Wikipedia, the free encyclopedia
This is an old revision of this page, as edited by 66.11.179.30 (talk) at 08:37, 24 February 2005. The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

A log-structured filesystem is a generalization of a journaling filesystem. In a log-structured filesystem, rather than being a conventional filesystem with an added journal log, the journal log itself is used as the fundamental basis for the filesystem, meaning that both filesystem meta-data and the filesystem data are journaled.

Such filesystems allow for accessing old versions of files (aka time-travel, snapshots) whereas journaling filesystems may lose or corrupt file content due to disk errors. Both types don't require long consistency checks on reboot because only the journal needs to be reviewed on startup, instead of the entire disk (as in UFS, FFS, ext2, etc.)

See Log File System for an implementation on NetBSD.