On Wed, May 07, 2008 at 12:58:22PM +0100, Wayne Stallwood wrote:
On Wed, 2008-05-07 at 11:19 +0100, Chris G wrote:
rdiff-backup only uses librsync at the very lowest level to work out the minimum data transfer to update a file as far as I can see.
Ahh in my magical little oversimplified world it was just a wrapper for rsync that added versioning :)
No, it's rather more than that! :-)
Of course you could just try and replicate the multiple backup versions in a script around rsync (or perhaps unison if it supports the following links thing) but I think it would be potentially quite tricky. I am not sure how rdiff-backup works, does it only keep one full copy of each file and then do cleverness with hard links and compression etc in the backup pool like backuppc does ?
I'm not sure what it does but it's much more sophisticated than a backup pool that rotates. Unless you delete old stuff it keeps a history back to when you started using it and you can restore anything from any time. Obviously it does eventually run out of space but it's pretty efficient. Currently my backup of my home directory is 30.7Gb and my home directory is 30.5Gb (the bulk is a Digikam photo album so that explains a bit).
I think in fact a better approach is probably to find the critical symbolic links and make sure I'm backing up what they point at. It turns out that I only needed to make one change to do this.