Jake Anderson <ya...@vapourforge.com> writes: > On 15/07/10 16:14, Daniel Pittman wrote:
[...] > We cant be the first people to come across this "branch office" scenario. Nope. Lots of people have, and wished there was a good solution, but it is a *really* hard problem. The difficulty curve in fixing it looks like a backward L, basically: the most trivial bit is trivial, then the problem more or less instantly gets insanely hard. > My goal is to have the branch office get a copy of all the files (think MS > office) without hitting performance at either end. something like this > rsync thing, with a distributed lock manager would be the solution to 99% of > the problem ...only then you pay the cross-WAN latency cost for every file open, at least, plus have to deal with the problem of disconnected operation, so still need conflict resolution, plus... > The only problem I can see is if person A in Newcastle wants person B in > Sydney to look at their file, they press save and then person B opens it > before the lazy copy has moved it over, Perhaps maintain a write lock on the > file until its synched? with user definable behaviour in the case of failure. > > At the moment the branch office is going to be working over a VPN back to > the main office, with all the files etc sitting inside VM's, the images of > the VM's will get rsynced nightly. Which all in all is a fairly craptacular > solution to be honest. Mmmm. For what it is worth, the least-worst solutions that I have found are: 1. Fire up a WebDAV server in each office to store "their" files, and make sure that it can be accessed through a fully public DNS name.[1] Some document management solutions offer WebDAV as part of their feature set, and might be a good addition to this. IIRC, SharePoint, in an MS environment, is one of 'em. 2. Go buy a copy of http://www.netdrive.net/ for every user that you have. (...or just use a Mac, since they do WebDAV OK too. :) 3. Use it to mount the WebDAV share for your users, because unlike the native Win32 WebDAV support, it doesn't suck.[2] Specifically, it works even if you are using a program that *isn't* Microsoft Office. That gives reasonable performance, akin to HTTP, for reading the remote file, plus some local caching, and it works right no matter where on the Internet your users are because they access a public URL, not a private CIFS share. However, not perfect, especially the server options, and not exactly replicated between sites. I don't know what the latest NetDrive offers in terms of offline operation, either. Daniel Footnotes: [1] Add SSL, authentication, etc to taste, of course. [2] Disclosure: this might not be true in Windows 7, or the latest Vista service packs, but because I have never used them I can't actually say. -- ✣ Daniel Pittman ✉ dan...@rimspace.net ☎ +61 401 155 707 ♽ made with 100 percent post-consumer electrons -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
