On Wed, Jan 25, 2012 at 04:29:02PM -0500, Chuck Lever wrote: > > On Jan 25, 2012, at 4:25 PM, J. Bruce Fields wrote: > > > On Wed, Jan 25, 2012 at 03:23:56PM -0500, Jeff Layton wrote: > >> I suggest that we only allow the reclaim of locks > >> on the original address against which they were established. > > > > I'm not sure what that means. > > > > If a server stops responding, the v4.0 client has two choices: it can > > either wait for the server to come back, and reclaim when it does. Or > > if it supports failover it can go find another server and perform > > reclaims over there. > > Honestly, I don't think that's possible in NFSv4.0. Well, it was *supposed* to be possible, wasn't it? I thought fixing up 3530 to make that work was part of what the discussion around http://datatracker.ietf.org/doc/draft-dnoveck-nfsv4-migration-issues/ was about? (OK, I should actually read that.) Agreed that there doesn't seem to be an agreed-upon way to do it now.... --b. > The richer information provided by fs_locations_info can allow the client to determine whether two servers share more than simply data. That information does not exist in NFSv4.0, so there's no way a client can expect that two servers lists in fs_locations results will always have the same NFSv4 state. > > Thus I believe that NFSv4.0 replication is limited to read-only data. But I have to go back and read that chapter of 3530 again. > > > I'm a little unclear how it does that, but I suppose it first tests > > somehow to see whether its existing state is supported, and if not, it > > establishes a new clientid with SETCLIENTID/SETCILENTID_CONFIRM using > > its old name, and then attempts to reclaim. > > > > You're now requiring it *not* to do that if it happens that the servers > > all rebooted in the meantime. How does it know that that's what > > happened? > > > > Or maybe that's not what you want to require, I'm not sure. > > > > --b. > > -- > > 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 > > -- > Chuck Lever > chuck[dot]lever[at]oracle[dot]com > > > > -- 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
