Neil Brown wrote: > > Suppose I have a mobile client such as a notebook computer which > changes networks from time to time - e.g. when "docked" it uses a > wired network, but when I "undock" it uses a wireless network. And > as I move around it might change from one wireless network to > another. This is quite a common scenario these days. > Is it at all reasonable to expect that I could have an NFS mounted > filesystem that continues to work across all of those changes? I think it is reasonable to expect with the changing network paradigm of mobile computing. Successful protocols/implementations always have adapted themselves to the changing (network) needs :) > I think that the only way to get the client to close and re-open the > socket would be to wait for 5 minutes with no IO requests. But that > would be hard to ensure. Any attempt to access any file will trigger > a request which will keep retrying which will keep the socket active, > so the client won't close it.... It doesn't seem to work anyway. The > RPC client appears to try to connect from the same source IP address, > though I haven't checked the code to be sure of this. > > Would it be worthwhile/practical to have a 'remount' mount option to > request that the socket be closed and re-opened? or better name would be 'reconnect'? > If there were any active locks, there is probably nothing useful that > can be done for them. Unless the client manages to send a NOTIFY to > the server before changing IP address, the server will never drop the > locks. Maybe "-o remount,reopen" would only work if "-o nolocks" > were in force. It's not an ideal solution, but it might be better > than the current situations? Definitely, it can make mobile clients life easier. And it looks to me that all of these can be done at the userspace itself. > I'm not sure whether NFSv4 makes this easier or harder. Can you > continue a client session (SET_CLIENTID) from a different IP address? > Can you change the callback address for a CLIENT once it is created? I think 'nolock' and 'nfs4' can't be used together and nfs4 always will enable locking. Thanks, -- Suresh Jayaraman -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
