WD MyCloud NFS Mount to Asus Merlin Router: NFS mount troubleshooting: "no such device"

Question

Goal: mount a UNIX NAS (WD myCloud) to a UNIX router.

What has been done (do not assume it is correct):

1. Checked router is running NFS client:

   ps | grep nfsd 
   

   19243 username 1376 R grep nfsd

2. Checked NAS is running NFS server from macbook:

   rpcinfo -T udp 192.168.X.XXX | grep nfs
      100003       2     tcp      0.0.0.0.8.1          nfs        unknown
      100003       3     tcp      0.0.0.0.8.1          nfs        unknown
      100003       2     udp      0.0.0.0.8.1          nfs        unknown
      100003       3     udp      0.0.0.0.8.1          nfs        unknown
   

3. Attempt to mount NAS directory use syntax:

   mount -t nfs server_IP_addr:/share_name /local_mount_point

   mount -t NFS 192.168.X.XXX:/shares/Public/Data /mnt/nas
   

   The error response:

mount: mounting 192.168.X.XXX:/shares/Public/Data/ on /mnt/nas failed: No such device

I am interested in understanding how to diagnose the cause of 'no such device'. Is there a procedure (series of command-line tests) that systematically flush out the issue?

Updates / Detailed Responses to Questions / Requests:

nfs server module not found and unable to load:

root@WDMyCloud root # service nfs status
-sh: service: not found
root@WDMyCloud root # systemctl status nfs-server
-sh: systemctl: not found
root@WDMyCloud root # lsmod | grep nfs
root@WDMyCloud root # modprobe nfs
modprobe: chdir(/lib/modules): No such file or directory   
root@WDMyCloud root # ipkg
-sh: ipkg: **not found**

ps command:

root@WDMyCloud root # ps | grep -i nfs
  375 root         0 SW<  [nfsiod]
 2813 root         0 SW   [nfsd]
 2814 root         0 SW   [nfsd]
 2815 root         0 SW   [nfsd]
 2816 root         0 SW   [nfsd]
 2817 root         0 SW   [nfsd]
 2818 root         0 SW   [nfsd]
 2819 root         0 SW   [nfsd]
 2820 root         0 SW   [nfsd]
11491 root      2592 S    grep -i nfs

showmount -e 192.168.X.X returns an empty export list

Answer 1

Special thanks to YurijGoncharuk who spent hours experimenting with NFS.

How to Mount a WD MyCloud NAS to Asus Merlin Router

• NAS: enable NFS =>WebUI =>Shares =>ShareName =>Share Access =>NFS Access=ON
• Verify NFS shares are available: showmount -e 192.168.X.XXX
• enable NFS services in router
• mount -t nfs 192.168.X.XXX:/NFS_share_name/ /mnt/nas -o nfsvers=3,nolock,_netdev,rsize=8192,wsize=8192

• mount -t nfs 192.168.X.XXX:/mnt/HD/HD_a2/Public /tmp/mnt/sda1/Download2/nas -o nfsvers=3,nolock,_netdev,rsize=8192,wsize=8192

• MacBook Client

  sudo mount_nfs -o resvport IP_Address:/NFS_share_name/ /local_mountpoint

  sudo mount_nfs -o resvport 192.168.X.XXX:/mnt/HD/HD_a2/Public /Users/user/nas