> From: Ian Kent <ra...@themaw.net> > > On Thu, 2011-06-16 at 20:20 +0100, Colin Simpson wrote: >> Hi >> >> I was just wondering what the thoughts (maybe plans) are for making >> autofs/nfs more dynamic in the new world of dynamic networking with >> the likes of Network Manager now being the default. > > I've read this a couple of times now and I'm still not sure what to say > because the mail is so open ended. But here are a few comments anyway. > > That might mean dbus integration which I've tried to avoid because, to > me, that looks really painful and AFAICT the documentation is lousy so > working out what the hell to do is difficult and frustrating. > > But that's not really the largest part of the work either, which I won't > try and go into now, because of the main difficulty described below. > >> >> We now have quite a few users with linux laptops and they want to see >> the standard automounts on these. But being laptops they frequently >> switch subnet, jump on WiFi and VPN etc. >> >> Most subsystems seem to play pretty well with this dynamic network >> environment and are hooked into NM (with SSSD doing a good job with >> off net credentials and directory services caching) >> >> Now I know that autofs/nfs is a much harder nut to crack given its >> heavy in kernel component, but I'd have thought the present >> non-dynamic behaviour is a bit of an anomaly. > > The issue is NFS. > > Dynamic fail-over for mounts has been on the NFS list of things to do > for over five years and is not done yet. I'm not even sure anything is > being done or has been done toward it. And that's just for the simpler > case of read-only mounts. > > I'm not sure that is what your after either but the difficulty would be > considerably more for read-write mounts. For example, although nfs > mounts are stateless (nfs4 is another matter entirely), they rely on a > file handle that is constructed based on server dependent information so > moving from one network to another and expecting mounts to just continue > to work is not going to be simple, if it is even possible.
For more information on NFS plans in this area, Colin, you could post your questions to linux-...@vger.kernel.org. The NFS version 4 protocol provides lots of opportunities for client-side fail-over support, even for read/write mounts. We're working on some of these pieces now, but it will be a while. The question of NFSv3 client-side fail-over support is more sticky, as Ian has pointed out. -- Chuck Lever chuck[dot]lever[at]oracle[dot]com _______________________________________________ autofs mailing list autofs@linux.kernel.org http://linux.kernel.org/mailman/listinfo/autofs
