How to fix Synology NFS mounting with 000 permissions (Permission denied)

Problem:

You have mounted a shared directory on your Synology NAS using NFS. The mount succeds, but when you try to access the mount point (e.g. ls /nas) you see a Permission denied error even if running as root.

Solution:

Go into the Synology NAS web UI, go into control panel, go to shared folder edit the permissions for the shared folder you’re trying to access (right click => edit)

You likely have checked the No access checkbox for the admin user. Uncheck it, then click OKon the bottom right.

Now your NFS share should work again (even without remounting).