Date: Tue, 1 Oct 2013 13:17:50 -0500
From: Malahal Naineni <malahal@us.ibm.com>
To: linux-nfs@vger.kernel.org
Subject: NFS with ActiveDirectory+Kerberos
Message-ID: <20131001181750.GA24424@us.ibm.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Sender: linux-nfs-owner@vger.kernel.org

Hi All,

We are using RHEL6.1 as an NFS server, and we have configured an RHEL6.2
system as an NFS client. We configured AD+Kerberos set up on both these
machines. The kerberos TGT ticket is set to expire after a long time,
but the kerberos service ticket is set to expire only after a short time
(10 minutes), but the service ticket is renewable!  NFS I/O fails around
when service ticket expires (EIO or EACCESS). If we retry the command
(or any command that generates NFS I/O), the service ticket gets renewed
and everything works until the next service expiry time.

Could this be an AD (Active Directory) related issue? Do auto renewing
service tickets work in NFS (nfs-utils-1.2.3-15.el6.x86_64)?  We have
tried with 10 hour service ticket expiry time as well. Same issue, the 
I/O fails after 10 hours!

I am not familiar with kerberos and NFS security. Is there a way to
manually (cron/script) renew those tickets and make it work without NFS
errors? I would appreciate any help.

Regards, Malahal.