places to look

• on the clients
  • /etc/fstab — Lists the shares that we automatically mount, along with their options. See nfs(5).
• on the server
  • /etc/exports — Lists the shares that we make available, along with their options. See exports(5).

polished solutions

• if you have uid/gid of 4294967294/4294967294, you should make sure that "NEED_IDMAPD=yes" is enabled

random search

• diagnostics
  • lots
  • lots
  • from the server
    • exportfs -v
  • from the client
    • showmount -e <host>
    • rpcinfo -p <host>