NFS client support for NFS version 3

modulename: nfsv3.ko

configname: CONFIG_NFS_V3

Linux Kernel Configuration
└─>File systems
└─>Network File Systems
└─>NFS client support for NFS version 3
In linux kernel since version 2.6.20 (release Date: 2007-02-04)  
This option enables support for version 3 of the NFS protocol
(RFC 1813) in the kernel's NFS client.

If unsure, say Y.

source code: