The situation is as follow :
Our company works two main production sites, communicating via WAN. We develop a software internally which uses about 100Gb of disk space on our servers (application data deployed to our customers with a lot of images). In order in improve performance, our network administrators choosed DFS replication (every 6 hours). This means that our users (people from within the company) do not have to wait (sometimes 2-3 hours) to download the needed files, because they are available locally (over LAN).
The problem is that the algorithm used by DFS replication is "Last Writer Wins". So, in case of simultaneous changes (during development/maintenance), the file with the latest date will win. I would like to avoid such data loss.
I am project manager for the overall develop process. What I want to do, is to introduce people to version control systems to tackle the simultaneous modifications problem. I plan to use Mercurial for several reasons, mainly because it is distributed, simple to explain, usable for personal use, free, and (most importantly) has great merging capabilities. However the benefits of the version control system when used locally (LAN) is lost because of the replication process (WAN) which doesn't know how to merge.
Some possible solutions are to :
use only version control over the WAN (hoping that compression will be enough to speed things up)
use only DFS, and track changes manually (error-prone)
find a work-around with both methods
The team is small (about 10 persons). Your help and experience is appreciated.