Ubuntu – Since Upgrading NFS and Ubuntu to 14.04, All NFS Mounts Are Failing

nfsUbuntu

Since upgrading my Ubuntu Machine, all my NFS mounts are hanging. I checked the syslog, and I'm seeing this now:

Sep 29 04:29:10 ip-10-10-10-10 kernel: [ 9589.594814] RPC: AUTH_GSS upcall failed. Please check user daemon is running.

All other methods of debugging NFS still show it up and running (telnet, rpcinfo, etc). What is the AUTH_GSS service and why does it need to be running? I've been running around on Google, but I can't see any reason why it wouldn't already be going.

** UPDATE **

In addition to this, I'm now seeing the following on the server:

Sep 29 05:55:12 ip-10-10-10-10 rpc.gssd[860]: ERROR: can't open /run/rpc_pipefs/gssd/clntXX/info: No such file or directory
Sep 29 05:55:12 ip-10-10-10-10 rpc.gssd[860]: ERROR: failed to read service info

** FURTHER DEBUGGING **

To be clear, it's absolutely running, and accepting connections from the client machine. I'm able to telnet over to 111 and 2049 from the client machine with no issue.

Best Answer

GSSAPI or the Generic Security Services Application Programming Interface is used by NFS (versions 3 and 4) when using Kerberos for authentication and encryption.

The ubuntu config file /etc/default/nfs-common has a few lines about this:

# Do you want to start the gssd daemon? It is required for Kerberos mounts.
NEED_GSSD=

Either configure Kerberos and GSS or make sure you don't use them.

There's a related bug report on launchpad that suggests either setting NEED_GSSD=yes or disabling GSS by blacklisting the rpcsec_gss_krb5 module (in /etc/modprobe.d/blacklist.conf, after which you need a restart).

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