I hope you already know how to allow NFS from proxmox host server. if not, you may read my earlier post:
I was actually receiving a error like below:
# mount -t nfsd nfsd /proc/fs/nfsd mount: nfsd is write-protected, mounting read-only mount: cannot mount nfsd read-only
My proxmox edition was 5.0-30 and my CentOS was 7.
However, this is a bit different rather looking the other one as mentioned above. I was experiencing connecting my Centos 7 LXC container to a NFS server in the network. The regular tweak didn’t work. So, had to spend a while googling the solution. Found the correct one on a forum thread. But eventually it worked. For this you need to edit the file
nano /etc/pve/lxc/<your container ID>.conf
Add the below line in the conf file:
Reboot the container. And now try to connect the NFS server. It should work.