"batched dry-run"... sort of

[leandro.batlle at fmc-ag.com]

I'd like to know if it's possible to run rsync in batch mode, but avoiding
transferring the deltas, just generating the batch file.
I'm looking for such a behaviour because overnight backup sessions are
often interrupted and daily snapshots (--link-dest) of remote servers are
truncated. Specially the ones using slow links.

Options:

1)    Using  -write-batch when mirroring volume within the remote server,
then transferring the batch file.
2)    Using  --list-only. Then iterate backup sessions, sort of
round-robin  way. (backup sequentially using the list between sessions,
then generate a new one)
3)    Using --partial-dir
4)    Using -write-batch combined with -dry-run

The first option wastes too much disk space. Second and third ones are
close to ideal because avoids "starvation": all files get backed up,
eventually. But they are not snapshots and files may not be consistent from
day to day (i.e. tables and indexes of a DB, stored in separate files).
Of course, there's no way to get snapshots every day, since the link is
complete.
The last option would be ideal but, unfortunately, is explicitly forbidden
by options.c. It seems to me that it is a protocol related impediment,
since --dry-run is always checked before any action in the
generator/receiver side.


Can anyone point me to a solution? If not, I'd like to propose "batched
dry-run" mode as a new feature. :)


Regards








Leandro Batlle
Fresenius Medical Care Argentina
Suipacha 1067 Piso 7 (1008)
Buenos Aires, Argentina
Tel.: +54-11-4130-1135
Fax: +54-11-4130-1111
e-mail: Leandro.Batlle at fmc-ag.com
http://www.fmc-ag.com.ar