rsync vs. iOra

[OVERGARD,KEN (HP-USA,ex1)]

I've looking into the possibility of using rsync for mirroring where we are
currently using iOra.

It looks like iOra has two main advantages over rsync:

	1) can calculate deltas across multiple files (i.e., blocks common
to two files will only appear once in the delta)
	2) can de-couple delta calculation and application (creates deltas
offline)

I'm pretty sure I can emulate (1) by simply making a tarball of the target
directory and having rsync work off that file, but it may already handle
that situation.

De-coupling as in (2) above is the tricky one.  It seems that one way to get
this behavior is to modify rsync so that where data would normally be
transferred to the client, the same data could be output to a file.
Likewise, the client could be modified to take its commands from the file
instead of from the server.  I don't know how feasible this would be...any
ideas?

Ken Overgard
Software Design Engineer
HP Advanced Solutions Lab