topic Re: NFS V4 locking in Operating System - Linux

NFS V4 locking

David Nixon — Mon, 07 Nov 2011 11:59:11 GMT

Have been testing some NFS version 4 exports from a RHEL 4.8 server

and its quckly become apparent that there are issues with locking.

Basically the fcntl(2) and lockf(2) system call interfaces don't work.

On an V4 mount these calls always fail with errno ENOLCK - no

locks available.

Contrary to what is stated by its man page, flock(2) does work over

NFS V3 or V4, at least from version FC13 and Scientific Linux clients.

Can anyone shed any light on the basic issue? I am wondering

if I need some Kernel update or other.. Currently running 2.6.18-164

Dennis Handly — Tue, 08 Nov 2011 03:36:15 GMT

Do you have to have a demon running on the server like HP-UX?

David Nixon — Tue, 08 Nov 2011 12:36:04 GMT

Yes the rpc.nfsd demons are still there under NFS Version 4 .

Anyway, I have tried V4 locking on a RHEL5 test server

and that all works as expected..

Someone related to me on the Red Hat forums that

they had had to revert to NFS V3 under RHEL4.

So I guess it is some sort of kernel issue, that

will,likely, never be resolved by now.