On Sat, Nov 04, 2017 at 09:50:58PM -0400, John Ratliff wrote: > On 11/4/2017 8:22 PM, John Ratliff wrote: > >We recently migrated our email storage to a server sharing the > >files with NFSv4 rather than NFS v3. We ran into a strange > >problem, so we wanted to find out if it was related to the NFS > >version or not. > > > >When I tried to mount the NFS share as an NFSv3 share, I was > >unable to do any file locking. I was unable to diagnose the > >problem, so I moved the disk back to the old NFS v3 server until I > >could do further testing. > > > >Is there a reason I might not be able to do a file lock on an NFS > >client with a server that does NFSv4 and NFSv3? > > > >The server and client are on the same subnet. There is no firewall > >between the two systems. hosts.allow was set to ALL: ALL on both > >client and server just to make sure that wasn't the problem. > > > >Reverting to the old NFSv3 server worked fine. Building another > >NFSv3 server didn't exhibit the problem either. So I'm not sure > >how to find out what the problem is. > > > >I used this program to test whether a file could be locked. > > > >--------------------- > >#! /usr/bin/perl > > > >use strict; > >use warnings; > > > >use Fcntl ':flock'; > > > >my $file = '/mnt/nfs3/test-file.lock'; > >open (my $fh, '>>', $file) or die; > >flock($fh, LOCK_EX) or die 'could not lock file'; > >close($fh); > >-------------------- > > > >Normally, it returns immediately. But on the new NFSv4 server, it > >times out and dies with 'could not lock file'. I don't know if > >that's the proper way to do file locking on NFSv3, but I know my > >mail server daemons can't do locking when that program fails, so > >it looks like a reasonable test. > > > >Any advice for how I can diagnose this problem? > > > >NFSv3 client machine: > > Ubuntu 14.04 > > Kernel 3.13.0 64-bit > > nfs-common version 1.2.8 > > > >/etc/fstab: > > 192.168.1.103:/mnt/nfs3 /mnt/nfs3 nfs tcp,soft,intr,nfsvers=3 0 0 > > > >NFSv3 server machine (the broken one): > > Debian 9 > > Kernel 4.9.0 > > nfs-common version 1.3.4 > > > >/etc/exports: > > /srv/nfs4 192.168.1.0/24(rw,sync,fsid=root,crossmnt,no_subtree_check) > > /srv/nfs4/nfs3 192.168.1.0/24(rw,sync,no_subtree_check,no_root_squash) > > > >NFSv3 server machine (the old functional one): > > Debian 8 > > Kernel 3.16.0 > > nfs-common 1.2.8 > > > >/etc/exports: > > /mnt/nfs3 192.168.1.0/24(rw,sync,no_subtree_check,no_root_sqaush) > > > > > After checking the rpcinfo -p outputs on both servers, I noticed the > status process wasn't running on the debian 9 server. It was not > enabled. After starting that process, the lock returns successfully. That would do it. Thanks for the followup.--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
