Return-Path: Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 11.3 \(3445.6.18\)) Subject: Re: NFS troubles From: Chuck Lever In-Reply-To: Date: Fri, 6 Apr 2018 12:24:21 -0400 Cc: Benjamin Coddington , Linux NFS Mailing List Message-Id: <7A560163-BA54-4051-9BB4-12087952987D@oracle.com> References: To: Orion Poplawski List-ID: > On Apr 6, 2018, at 12:07 PM, Orion Poplawski wrote: >=20 > On 04/03/2018 09:44 AM, Orion Poplawski wrote: >> Kernel is 3.10.0-693.21.1.el7.x86_64 I don't have Red Hat support = for these >> systems. >>=20 >> I discovered that I'd been forcing vers=3D4.0 mounts in order to work = around a >> mounting issue. =20 >=20 > And I'm back to seeing the mount issue at boot. Here's the situation = - we're > forcing kerberos on the public network, but allowing sec=3Dsys on some = private > networks: >=20 > /etc/exports: > / -ro,async,fsid=3D0 192.168.1.0/24(sec=3Dsys) > 192.168.2.0/24(sec=3Dsys) *.nwra.com(sec=3Dkrb5) > /export/home -rw,async,nohide 192.168.1.0/24(sec=3Dsys) > 192.168.2.0/24(sec=3Dsys) *.nwra.com(sec=3Dkrb5) >=20 > So for a while after boot, attempts to mount with sec=3Dsys fail: >=20 > # mount -t nfs4 -s -o > = sec=3Dsys,intr,rsize=3D262144,wsize=3D262144,noatime,lookupcache=3Dpositiv= e,actimeo=3D1 > earthib.cora.nwra.com:/export/home/greg /mnt > mount.nfs4: Operation not permitted >=20 > But then later they work: >=20 > # mount -t nfs4 -s -o > = sec=3Dsys,intr,rsize=3D262144,wsize=3D262144,noatime,lookupcache=3Dpositiv= e,actimeo=3D1 > earthib.cora.nwra.com:/export/home/greg /mnt > # umount /mnt >=20 > This can cycle back and forth. >=20 > I've attached a packet capture of some failed mount attempts. It = seems that > even with specifying sec=3Dsys, some kerberos stuff is going on. >=20 > It appears to be related to mounting a different sec=3Dkrb5 mount over = the > public network from the same server. While that mount is active, the = sec=3Dsys > mounts fail. When it is unmounted, they work. At least now I think I = can > work around this... For NFSv4, the client is going to use krb5i to do lease management even on sec=3Dsys mounts. An NFSv4 server has to know for sure when it is = talking to the same client on different network interfaces or with different security flavors. Thus the client has to use the same security flavor = for lease management on all of its mounts of that server. That's not = controlled by the sec=3D mount option. I assume that "but then later" lasts only a few multiples of the = server's lease time (90 seconds by default)? Clients that use only the private network interface should be able to = use sec=3Dsys. But clients that use both the public and private interfaces = should need to use sec=3Dkrb5 on both. -- Chuck Lever