Problem : file access is slow over the WAN
We currently host all files at our central office, which has a 10mbit connection to our WAN (an ATM network). All remote sites are on local 3mbit ADSL (does only 1 to 1.5mbit really). PVC points towards the main site (10mbit). We use EIGRP but have a very static network, so change never occur really. Router (Cisco all the way) are not running out of CPU nor memory, problem is not there.
We have 1 main file server. It's fast enough (XEON dual processor with 1gig memory). The problem here is really not a server hardware issue. File access is fast enough at the main site, only at remote site with 10+ users, things get a little to slow at times. Problem is not with the server as file access is fast when used locally.
Problem is related to the ADSL loop that are too slow when network traffic peek occurs. We do not want to invest on faster ADSL (can hardly get faster anyways). What I will accept as answet will be a way to cache files at the remote sites (even if that means setting up local servers). My main constraint is backup, they are all done at the main office and I don't want to backup file remotely on the WAN at night.
I would want a solution that provides some kind of caching + with syncronisation at the main site.
Limiting the bandwith use would is almost essential ( I don't want the sync to take 50% of the bw half the day). It has to be reliable. It should be usable on Windows 2000/2003 or on Linux.
I'll answer any questions or give more informations on demand,