NFS mounts not working in ubuntu 16.04?

Question

Before I upgraded to ubuntu 16.04 from 14, I used to be able to mount and access folders on WDMyCloud drives. Now I get the following error:

ls: Cannot open directory '/home/nas/Public': Operation not permitted.

I did not change anything on WDMyCloud. showmount -e 192.168.0.19 produces:

/nfs *

exports entry on the server:

/nfs *(rw,sync,no_subtree_check,insecure,crossmnt)

user with uid=1000 and gid=1000 on server can access all files. My uid on client is also 1000: id balaji produces this:

uid=1000(balaji) gid=1000(balaji) groups=1000(balaji),4(adm),24(cdrom),27(sudo),30(dip),46(plugdev),110(lxd),113(sambashare),119(lpadmin)

fstab entry on client (it is a single line)

192.168.0.19:/nfs /home/nas nfs rw,udp,vers=3,soft,intr,rsize=8192,wsize=8192 0 0

ls /home/nas produces

Public

ls /home/nas/Public
ls: cannot access '/home/nas/Public/': Operation not permitted

I started having this problem after upgrading to ubuntu 16.04. Any suggestions?

Solution

Each NFS share must be explicitly exported in /etc/exports.

Can also try sudo apt-get install --reinstall nfs-common nfs-utils just in case.

In /etc/fstab, rw,udp,vers=3,soft,intr,rsize=8192,wsize=8192 can be replaced with just auto - over-specifying could sometimes cause some odd issues.

Comments

[steeldriver]

Is /nfs/Public a separate filesystem on the server side (as suggested by the crossmnt option)? Are you explicitly exporting it?

[bshyamkumar]

Thanks, that fixes it. Looks like something changed on WdMyCloud recently and my upgrade had nothing to do with it breaking.