Return-Path: trond.myklebust@primarydata.com MIME-Version: 1.0 In-Reply-To: <5462608B.1090607@RedHat.com> References: <5462608B.1090607@RedHat.com> Date: Tue, 11 Nov 2014 15:43:05 -0500 Message-ID: Subject: Re: mount default minor version behavior From: Trond Myklebust To: Steve Dickson Cc: Benjamin Coddington , Linux NFS Mailing List Content-Type: text/plain; charset=UTF-8 List-ID: On Tue, Nov 11, 2014 at 2:16 PM, Steve Dickson wrote: > > > On 11/11/2014 10:01 AM, Trond Myklebust wrote: >> One thing you should note when doing this: the current parser for >> /etc/nfsmount.conf does not support minor versions. I think it needs >> to, so that we can continue to use it to set defaults. > Well setting Nfsvers=4.1 will give you a v4.1 mounts (assuming > the server supports v4.1. but setting Defaultvers=4.1 does > give you a v4.0 mount, which will need to be fixed. > >> >> ...and to answer your questions above, I think that we should be able >> to specify a 'default nfsv4 minor version' in /etc/nfsmount.conf, and >> then negotiate down from there. >> IOW: extend the 'Defaultvers' and 'Nfsvers' options to support 4.0, >> 4.1, 4.2,.... > Well Defaultvers is a negotiation with the server, Nfsvers is not. > So when Nfsvers set set there is no negotiation, they get what is > set to (aka 3, 4, 4.0, 4.1, just like the command line). > > With Defaultvers its a negotiation so set it to highest > version and let it go... I'm not sure we need another > variable to complicate things... > >> >> The result should be that If I do 'mount -t nfs' with no '-overs' >> option, then we start at 4.1 (if that is the default in >> /etc/nfsmount.conf) and then try 4.0, 3, 2 in that order. >> If I do 'mount -t nfs -overs=4', then again consult /etc/nfsmount.conf; >> - if there is a default matching a v4 minor version, then start at >> that and negotiate down (but stop at 4.0). > Again, I'm thinking this type of complexity is not needed (especially > from a testing matrix point of view). > > besides, if someone is specifying a version on the command line, is most likely > they are not going to be using /etc/nfsmount.conf as all... > >> - if there is no default in /etc/nfsmount.conf, then perhaps assume a >> default of 0(????) > I'm thinking why not default to the better minor version?? 4.1 => 4.0 => 3 So at which minor version do you start? 4.10, 4.100?... We don't want to have to recompile mount every time we add a new minor version in order to bump the maximum number, which is why I think we want to use /etc/nfsmount.conf and Defaultvers to define that (and assume '0' if undefined). -- Trond Myklebust Linux NFS client maintainer, PrimaryData trond.myklebust@primarydata.com