Convert dss to lopsub.
[dss.git] / README
1 dss creates hardlink-based snapshots of a given directory on a remote
2 or local host using rsync's link-dest feature.
3
4 dss is admin friendly: It is easy to configure and needs little
5 attention once configured to run in daemon mode. It keeps track of
6 the available disk space and removes snapshots if disk space becomes
7 sparse or snapshots become older than the specified time. Also, due
8 to the hardlink-based approach, there is only one type of backup.
9 Hence no full, incremental or differential backups need to be
10 configured, and there is no database to maintain.
11
12 dss is also user-friendly because users can browse the snapshot
13 directories without admin intervention and see the contents of the file
14 system at the various times a snapshot was taken. Each snaphot looks
15 like a full backup, so users can easily restore accidentally removed
16 files by using their favorite file browser to simply copy files from
17 the snapshot directory back to the live system.
18
19 dss gives your data an additional level of security besides the usual
20 tape-based backups: If the file server goes down and all data is lost
21 you can simply use the most recent snapshot as an immediate replacement
22 -- no need for a restore from tape that takes days to complete.
23
24 Snapshot pruning takes place in a dyadic fashion: Many recent snapshots
25 are available, but the number of snapshots per time interval decreases
26 exponentially. For example, one can configure dss so that it keeps
27 16 snapshots not older than one week, 8 snapshots between one and
28 two weeks old, 4 snapshots between two and three weeks old, and so on.