A bunch of hosts all connected to each other.

I'd like to have a directory where a group of hosts can dump files and all access, synchronising with each other their changes automatically and transparent to the user.

How can I have it so that rsync updates both ways?

* host A asks host B for a list of files, modification dates, checksums
* then applies the rules to select which files it will fetch from B
--> if A owns the file then do not get modifications from B
--> files differ, then select newer file
* then fetches them
* and so on for each host...

Any ideas?

Are these going to be user modified files? if so how will they be modifying the files?

If an 'application' or script is going to be modifying the files you are going to have to check timestamp when opening the file for editing, and then compare the timestamp before saving to see if it has changed. If so then save a local copy then rsync.

That's the best i could come up with right now. Hope it helps.