NFS client and server support is required in case it’s disabled by default.

Navigate to File Systems -> Network File Systems and select the following option:

• select “Network File Systems” (CONFIG_NETWORK_FILESYSTEMS=y)
• select “NFS client support for NFS version 2” (CONFIG_NFS_V2=y)
• select “NFS client support for NFS version 3” (CONFIG_NFS_V3=y)
• select “NFS client support for NFS version 4” (CONFIG_NFS_V4=y)
• select “NFS server support” (CONFIG_NFSD=y)
• select “NFS server support for NFS version 3” (CONFIG_NFSD_V3=y)
• select “NFS server support for NFS version 4” (CONFIG_NFSD_V4=y)