On 11/12/2014 10:28 AM, Trond Myklebust wrote: > On Wed, Nov 12, 2014 at 10:10 AM, Steve Dickson <SteveD@xxxxxxxxxx> wrote: >> >> >> On 11/12/2014 09:31 AM, Trond Myklebust wrote: >>>> My point is I don't think we need another variable, say >>>>> DefaultMinVers, that defines the minor version of v4. I'm >>>>> thinking that's its overkill and adds unnecessary complexity. >>>>> >>> I never said we do. >> Ok... I misunderstood... >> >>> >>> I think we're in agreement mostly; the only point where I see >>> disagreement is when Defaultvers is unset. >>> My position is that in that situation, we don't know what starting >>> point to use for minor version negotiation, and so we should just >>> default to minor version 0: if the sysadmin want a different default, >>> then the answer is to set Defaultvers... >> Gotta... and there is a disagreement... I saying we make the >> default the highest supported minor version. With the >> Linux client and server that's v4.2. So when no option is >> given and Defaultvers is not set, try 4.2, then 4.1 and >> then 4.0 and finally v3. > > Only for Linux 3.11 and newer, and only if they enable CONFIG_NFS_V4_2 > / CONFIG_NFSD_V4_SECURITY_LABEL. Being dynamic is never easy! ;-) The server has /proc/fs/nfsd/versions file that defines the supported versions. Maybe we can come up with something on the client that would tell what protocols are supported... > > Unless we want to have different defaults for older kernels, this sort > of implies that we're moving in the direction of coupling the > nfs-utils releases more tightly to the kernel version. I'm neutral to > that, but I do want to call it out. > >> But I do see your point of not having to recompile mount >> when we want to change the default minor release so >> how that default is set is the question... Maybe >> an environment variable?? > > That's still something that requires a user or sysadmin action, and it > wouldn't really play well with autofs and its ilk. As Marie Antoinette > would say: "Let them edit /etc/nfsmount.conf" Clever.. :-) > >> One down side of being the aggressive with minor version >> negotiation is legacy servers (aka AIX). Today we >> don't negotiate well with those types of servers... >> Its not our fault, but is a problem... > > Is this because they don't implement that part of RFC3530? The server returns the wrong type of error when a v4 mount is done so the mount fails instead of rolling back to v3. steved. -- 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
