1*4fed598aSRyusuke Konishiconfig NILFS2_FS 2*4fed598aSRyusuke Konishi tristate "NILFS2 file system support (EXPERIMENTAL)" 3*4fed598aSRyusuke Konishi depends on BLOCK && EXPERIMENTAL 4*4fed598aSRyusuke Konishi select CRC32 5*4fed598aSRyusuke Konishi help 6*4fed598aSRyusuke Konishi NILFS2 is a log-structured file system (LFS) supporting continuous 7*4fed598aSRyusuke Konishi snapshotting. In addition to versioning capability of the entire 8*4fed598aSRyusuke Konishi file system, users can even restore files mistakenly overwritten or 9*4fed598aSRyusuke Konishi destroyed just a few seconds ago. Since this file system can keep 10*4fed598aSRyusuke Konishi consistency like conventional LFS, it achieves quick recovery after 11*4fed598aSRyusuke Konishi system crashes. 12*4fed598aSRyusuke Konishi 13*4fed598aSRyusuke Konishi NILFS2 creates a number of checkpoints every few seconds or per 14*4fed598aSRyusuke Konishi synchronous write basis (unless there is no change). Users can 15*4fed598aSRyusuke Konishi select significant versions among continuously created checkpoints, 16*4fed598aSRyusuke Konishi and can change them into snapshots which will be preserved for long 17*4fed598aSRyusuke Konishi periods until they are changed back to checkpoints. Each 18*4fed598aSRyusuke Konishi snapshot is mountable as a read-only file system concurrently with 19*4fed598aSRyusuke Konishi its writable mount, and this feature is convenient for online backup. 20*4fed598aSRyusuke Konishi 21*4fed598aSRyusuke Konishi Some features including atime, extended attributes, and POSIX ACLs, 22*4fed598aSRyusuke Konishi are not supported yet. 23*4fed598aSRyusuke Konishi 24*4fed598aSRyusuke Konishi To compile this file system support as a module, choose M here: the 25*4fed598aSRyusuke Konishi module will be called nilfs2. If unsure, say N. 26