What to use for synchronizing data on multiple hosts with NetBSD?

[Thomas Klausner <wiz%NetBSD.org@localhost>]

Hi!

What is the best solution on NetBSD to keep data on three machines in
sync? One may be used as mostly-always available central machine, but
changes may happen on all of them, and I don't want to lose access to
the data if the central machine is not there.

1. NFS is not a solution, because the data is only available if the
server is there.
2. rsync is not the solution because I have to manually check which
machine had the latest changes to the files.
3. hg/git/... is not the solution because it's inefficient for this
use -- it duplicates the data (I'm interested in binary data, not well
compressible)
4. afs is not the solution, because I can't get it to work on NetBSD

What do you recommend for this use case on NetBSD?
 Thomas