RPC: Enable dprintk debugging

configname: CONFIG_SUNRPC_DEBUG

Linux Kernel Configuration
└─>File systems
└─>Network File Systems
└─>RPC: Enable dprintk debugging
In linux kernel since version 3.1 (release Date: 2011-10-24)  
This option enables a sysctl-based debugging interface
that is be used by the 'rpcdebug' utility to turn on or off
logging of different aspects of the kernel RPC activity.

Disabling this option will make your kernel slightly smaller,
but makes troubleshooting NFS issues significantly harder.

If unsure, say Y.

selects
CONFIG_DEBUG_FS


is selected by
CONFIG_NFS_DEBUG