(Illustration by Gaich Muramatsu)
On Sat, Feb 09, 2002 at 12:25:50PM -0500, Yan Seiner wrote: > I have two offices joined by a wan. Currently we are mirroring files > between the offices using unison, but that is not working very well. > > We need a more robust solution. > > We are getting more bandwith - a minimum of 128Kbit/sec; possibly as > high as 640Kbit/sec SDSL. > > We sync typically about 100MB / day with several hundred files. > a) coda can work with this limited bandwith This seems to be a pretty common scenario, however. Coda's server replication is quite bandwidth intensive, i.e. when resolving conflicts files are being fetched to one server and then redistributed. Furthermore, clients need to check the attributes of objects on all servers in a replicated group as it is the clients that detect the actual version differences and trigger the resolution. So using Coda for it's replication won't work in this situation. You could use Coda servers on both sites that are not replicating a volume between each other. So the volumes of 'local' users would be stored on the 'local' server. The problems here are, which site hosts the 'root-volume' of the /coda tree located as the remote site will suffer from the low bandwidth link, and although large client caches can eliminate some of the data fetches across the link, it's each client for itself, so even with only minimal sharing the amount of cross-site traffic is still considerable as it's N clients * M amount of shared data. > b) coda is stable enough to use in production It depends, my typical answer would be no, there are still known bugs and problems that are pretty hard to solve. Administratively it is not an easy system to set up and maintain, and the optimistic replication sometimes presents users with conflicts they don't want to deal with especially when there is a deadline. But for a small setup with only a few servers, users that are adaptive enough to work from the local disk while a problem is being resolved and an knowledgable administrator it can work reasonably well. i.e. It works here at CMU 24x7 with 6 servers, and about 25 users (typically 5-10 active clients during the day, so I'm guessing only about 5 active users that use Coda as their main means of keeping their data with them when counting both their desktops and laptops) JanReceived on 2002-02-09 13:35:07