Incremental Storage

[Max Kipness]

Hello,

I've been trying to figure out how to control the space required for
backups using rsync, large files, and an incremental backup scheme. In
particular, I've got two customers in which I'm creating Exchange
backups using the built-in MS backup, then rsyncing an exchange.bks file
nightly. One customer has a 4.3GB exchanges.bks file, and although rsync
works wonderfully by only sending 43mb worth of changes to this file
across the line, using hard links obviously causes incremental
directories of at least 4.3GB daily. With 30 days of incremental, this
adds up. 

I've looked at rdiff-backup, but do not like it as it's so different
than rsync. I've got a lot of scripting built around rsync and I like
the way it handles file/dir selections, so I will not consider
rdiff-backup.

I've been experimenting with rdiff itself and trying to figure out a
formula for creating delta files of only the changes to the Exchange.bks
file and using these delta files in the incremental directories, instead
of creating the hard links. I've gotten it to work, but not in a
rotational scheme where you always save only the latest copy and the
deltas, and can easily restore (patch) using just the latest and the
delta.

Has anybody found a solution for this? Or is there any other tool out
there that automates this? Again, rsync works great for the transfer,
but storing data incrementally is becoming the problem.

Would be nice if a future version of rsync created rdiff incrmentals as
an alternative option to 'cp- al' or 'link-destination'.

Thanks,
Max