[Discuss] rsnapshot vs. rdiff-backup

[Richard Pieri]

Kent Borg wrote:
> What mechanisms do other systems have to make this easier?  Some
> internals-to-internals data transport that is more efficient,
> opportunistic, etc., than a file interface?

Advfs has vdump and vrestore. ZFS has send and receive, and the native 
Solaris tar and cpio retain ZFS file attributes. XFS has xfsdump and 
xfsrestore. AFS has an impressive backup system built on the clone 
mechanism.

Linux LVM has... er... dd. It works for replication and for tape dumps 
but it isn't good for backups. To restore a single file you need to 
restore the base volume and then restore all of the relevant snapshots 
made against it.

Btrfs doesn't offer even that much. Neither GNU tar nor GNU cpio retain 
extended attributes. rsync is file system to file system and whether or 
not it retains extended attributes depends on the source and target file 
systems. rdiff-backup is superior to rsync in this regard in that it 
attempts to retain extended attributes across file systems but it still 
shares rsync's limitations: no tapes or other archive streams. The 
closest you can get to a 1:1 backup that I'm aware of is the port of 
BSD's cpio using libarchive, but I'm not sure if it retains all of the 
Btrfs file attributes.

-- 
Rich P.