Denis Croombs <denis at croombs.org> wrote: > I want to build 2 servers (both running samba) to provide > file storage to 2 offices (approx 100 miles apart, linked > via DSL) but all data writen to 1 server must also be saved > to the other server. What do you want to synchronize? Directory services? User authentication? Or files? Directory and user authentication are very doable. File services are typically not, or limited. > Both servers would also allow users to access the data via > a VPN thus allowing 1 office with a failed server to access > the other server via the vpn and still see the data from both > offices. You're going to _saturate_ your link between the two offices if you start synchronizing files in real-time. Unless you have something like a 4+ T-1s, or a 6+Mbps SDSL (i.e., synchronous DSL -- 6Mbps upload as well as download), you're going to find you're not going be able to do this in "real-time." At the best, you can use rsync to synchronize files at several points in the day -- maybe lunch-time and middle of the night. To get real-time, you're going to find the load on your network will be self-defeating. > I currently have 1 server working but we want to add the > second office to the system. (Currently 1 office has 10 users > and the second office has 1 user connected via VPN ) but the > second office will have 20 within 12 months and the first > will have 35 soon )) > Has anyone done anything like this ? Yes and no. Yes, I've done it. I've done it at high speed in the same closet (or nearby closet with SAN) with the same storage. NFS/Samba with failover c/o Mission Critical Linux (now part of RHEL). You need multi-targetable hardware (not cheap). But no, I haven't done it (nor would I do it) over a VPN link. You'll saturate it quickly. File server clustering is designed for high speed connections between servers and their storage. > I am currently reading & unpicking http://www.linux-ha.org/ > to see what that gives me. "High-availability" (HA) doesn't necessarily mean "failover." Most HA implementations are for read-only web services, destination NAT (DNAT), etc... When you start talking failover of network file servers, then you start talking mega-$$$, lots of bandwidth/synchronization requirements, hardware, etc... to do it real-time. GFS reduced the $$$ and same closet requirement, but it also expoentially increases bandwidth and other costs. At best, you'll have to do it non-real-time, using something like rsync. It won't be fail-over at all. > Any clues/comments very welcome, even if you think I am mad > ! I don't think you're mad. But I don't think you're aware of what is all involved with real-time failover of network file services. And it's really going to be near impossible over low-throughput Internet connections. I'd look to non-real-time rsync instead, running off-hours. That's the best you can do unless you have a lot of bandwidth and a lot of money. The majority of the HA stuff will _not_ apply. ;-> -- Bryan J. Smith | Sent from Yahoo Mail mailto:b.j.smith at ieee.org | (please excuse any http://thebs413.blogspot.com/ | missing headers)