NFS client support for NFS version 2

modulename: nfsv2.ko

configname: CONFIG_NFS_V2

Linux Kernel Configuration
└─>File systems
└─>Network File Systems
└─>NFS client support for NFS version 2
In linux kernel since version 3.1 (release Date: 2011-10-24)  
This option enables support for version 2 of the NFS protocol
(RFC 1094) in the kernel's NFS client.

If unsure, say Y.

source code: