You need to perform several steps to make NFS work, each step may be slightly different for your OS. Below are the steps for CentOS 7, both server and clients.

NFS server on CentOS 7

Firewall

Open up the firewall on the project-private network:

sudo firewall-cmd --permanent --zone=trusted --add-source=10.0.0.0/8
sudo firewall-cmd --reload

Check with:

sudo firewall-cmd --zone=trusted --list-all

Expected output:

trusted (active)
  interfaces: 
  sources: 10.0.0.0/8
  services:
  [...]

NFS server

Install the NFS SW:

sudo yum install nfs-utils

Create the root directory of the tree to export. The name chosen here, /export-nfs, is an example: you are free to use a different path.

sudo mkdir /export-nfs

You will need the network address and mask of your project’s private network. If your VM’s address on the private network is 10.X.Y.Z, then the private network is 10.X.Y.0/255.255.224.0.

Edit the configuration file /etc/idmapd.conf, line 5: uncomment and change to your domain name

Domain = server.world

Edit the configuration file /etc/exports and add a line for our export. Replace /export-nfs with the root you have chosen, replace 10.X.Y.0/255.255.224.0 with your project’s private network address and mask.

/export-nfs  10.X.Y.0/255.255.224.0(rw,no_root_squash)

Start the daemon:

sudo systemctl enable rpcbind nfs-server
sudo systemctl restart rpcbind
sudo systemctl start nfs-server

NFS clients

Optionally open the firewall.

Install the NFS package (see above).

Create a local mount point. The name chosen here is arbitrary, you are free to chose a different path.

mkdir /mount-nfs

Mount the NFS volume manually:

# REPLACE
# 10.X.Y.S with the server's address,
# /export-nfs with the server's export root and
# /mount-nfs/ with your local mount point
mount -t nfs 10.X.Y.S:/export-nfs /mount-nfs/

Check the mount:

mount

Expected output:

[...]
10.X.Y.S:/export-nfs on /mount-nfs type nfs4 > (rw,relatime,vers=4.0,rsize=131072,wsize=131072,namlen=255,hard,proto=tcp,port=0,timeo=600,retrans=2,sec=sys,clientaddr=10.X.Y.C,local_lock=none,addr=10.X.Y.S)

Test by writing to a file in the client’s /mount-nfs and reading on the server’s /export-nfs and vice versa.

Make permanent over reboots by adding the following line to file /etc/fstab but replace 10.X.Y.S with the server’s address:

10.X.Y.S:/export-nfs	/mount-nfs nfs4 defaults  0 0

See also: www.unixmen.com/setting-nfs-server-client-centos-7