| Ryusuke Konishi | 4fed598 | 2009-07-12 11:13:55 +0900 | [diff] [blame^] | 1 | config NILFS2_FS |
| 2 | tristate "NILFS2 file system support (EXPERIMENTAL)" |
| 3 | depends on BLOCK && EXPERIMENTAL |
| 4 | select CRC32 |
| 5 | help |
| 6 | NILFS2 is a log-structured file system (LFS) supporting continuous |
| 7 | snapshotting. In addition to versioning capability of the entire |
| 8 | file system, users can even restore files mistakenly overwritten or |
| 9 | destroyed just a few seconds ago. Since this file system can keep |
| 10 | consistency like conventional LFS, it achieves quick recovery after |
| 11 | system crashes. |
| 12 | |
| 13 | NILFS2 creates a number of checkpoints every few seconds or per |
| 14 | synchronous write basis (unless there is no change). Users can |
| 15 | select significant versions among continuously created checkpoints, |
| 16 | and can change them into snapshots which will be preserved for long |
| 17 | periods until they are changed back to checkpoints. Each |
| 18 | snapshot is mountable as a read-only file system concurrently with |
| 19 | its writable mount, and this feature is convenient for online backup. |
| 20 | |
| 21 | Some features including atime, extended attributes, and POSIX ACLs, |
| 22 | are not supported yet. |
| 23 | |
| 24 | To compile this file system support as a module, choose M here: the |
| 25 | module will be called nilfs2. If unsure, say N. |