Create and Export an NFS Server in Linux

Create and Export an NFS Server

NFS or Network File System is a commonly known method for network file sharing on Linux hosts. We will create and export an NFS server.

Table of Contents


In this article, we will create and export an NFS server in Linux using two CentOS7 virtual machines (VMs) to represent the client and the server.

Racked Server background with Engineer holding a Laptop

Image by Christina Morillo from Pexels

Before the days of high-powered storage appliances from tech giants like Netapp, DELL/EMC Isilon, and Hewitt Packard (HP), there needed to be an alternative way to store and share data when local hard disk space was limited and in short supply. The NFS protocol was born out of that need. It allowed end-users to share storage space over a network.

Pre-Installation Checks

Before we begin, this tutorial assumes you have a RHEL7 or CentOS7 machine running with root or the sudo privileges to become root. First things first, check to see if the nfs-utils package is installed on your machine. If not, make sure it’s installed, running, and enabled to auto start after a reboot of your machine. To check if NFS is installed on your system, run the following command.

					[admin@vm1 ~]$ sudo systemctl status nfs.service

The output below represents a running NFS service and if this service is running on your machine, you should see a similar output.

					[admin@vm1 ~]$ sudo systemctl status nfs.service
Loaded: loaded (/usr/lib/systemd/system/nfs-server.service; disabled; vendor preset: disabled)
Active: active (exited) since Tue 2022-02-01 12:16:52 EST; 6s ago
Process: 3191 ExecStartPost=/bin/sh -c if systemctl -q is-active gssproxy; then systemctl reload gssproxy ; fi (code=exited, status=0/SUCCESS)
Process: 3174 ExecStart=/usr/sbin/rpc.nfsd $RPCNFSDARGS (code=exited, status=0/SUCCESS)
Process: 3172 ExecStartPre=/usr/sbin/exportfs -r (code=exited, status=0/SUCCESS)
Main PID: 3174 (code=exited, status=0/SUCCESS)
CGroup: /system.slice/nfs-server.service
Feb 01 12:16:52 systemd[1]: Starting NFS server and services...
Feb 01 12:16:52 systemd[1]: Started NFS server and services.

Install the nfs-utils package

					[admin@vm1 ~]$ sudo yum -y install nfs-utils

Starting and enabling NFS

To start the NFS service, run the following command (below):

					[admin@vm1 ~]$ sudo systemctl start nfs.service

To enable the running NFS service so it auto starts after a system reboot, run the following command (below):

					[admin@vm1 ~]$ sudo systemctl enable nfs.service
Created symlink from /etc/systemd/system/ to /usr/lib/systemd/system/nfs-server.service.

Configure the firewall for NFS

Next, ensure the necessary ports are allowed on your local firewall for NFS and NFS-related services.


[admin@vm1 ~]$ sudo firewall-cmd --permanent --add-service=rpc-bind
[admin@vm1 ~]$ sudo firewall-cmd --permanent --add-service=mountd
[admin@vm1 ~]$ sudo firewall-cmd --permanent --add-service=nfs
[admin@vm1 ~]$ sudo firewall-cmd --permanent --add-port=2049/tcp
[admin@vm1 ~]$ sudo firewall-cmd --permanent --add-port=2049/udp
[admin@vm1 ~]$ sudo firewall-cmd --reload

Finally, run the firewall-cmd --list-all command to list all firewall rules and verify all the necessary ports and services are allowed.

firewall-cmd --list-all command output

Photo by admingeek from Infotechys

Export the NFS share to the client

Now that we’ve established NFS is running and enabled properly on the server instance, we can proceed with creating a mount point to export to the client instance. Using the system storage manager (SSM), we created a 10GB mount point called nfs_share and made it persistent on this server by adding an entry for it to the /etc/fstab (see image below).

Visit the “Introducing the System Storage Manager (SSM)” article for instructions on how to create logical volumes and filesystems using SSM.

The /etc/fstab entry for nfs_share

Photo by admingeek from Infotechys

To begin exporting the share, we need to first make the following entry (below) into the /etc/exports file.

					[admin@vm1:~] $ sudo cat /etc/exports

NOTE: The IP address in the output (above) belongs to the client host we are exporting the nfs_share to. The IP address entry in your /etc/exports file should match with the IP address of your client host.

Furthermore, the entry above will allow our client server with IP address, to mount nfs_share with read and write permissions. In addition, the sync option ensures all transfers to disk are committed to the disk before the write request by the client host is completed.

NOTE: By default, if the rw option is not specified in the /etc/exports file, the nfs_share will export with read-only permissions. There are other options you can specify in /etc/exports for access control purposes. Consult the man pages (man exports) for more details.

Using the exportfs command, export the nfs_share filesystem to the client host.

					[admin@vm1 ~]$ sudo exportfs -va
[sudo] password for admin:

Configure the firewall (NFS client)

Next, SSH into the client server and ensure the firewall rules allow for NFS and NFS-related ports and services. Reference the Configure the firewall to allow NFS ports on the server section and repeat those steps on the client host.

Also, verify the firewall rules are applied and working properly.

					[admin@vm2:~]$ sudo firewall-cmd --list-all
public (active)
target: default
icmp-block-inversion: no
interfaces: eth0
services: dhcpv6-client mountd nfs rpc-bind ssh
ports: 2049/tcp 2049/udp
masquerade: no
rich rules:

Mounting the NFS share on the client

Before we proceed with mounting the /nfs_share filesystem, ensure the nfs-utils package is also installed on the client host. Do not start or enable any NFS services as it’s not required on the client host.

					[admin@vm2:~]$ sudo yum -y install nfs-utils

Next, using the mount command, we can mount the nfs_share on the client with the following command (below).

					[admin@vm2:~]$ sudo mount /nfs_share

The IP address (above) belongs to the NFS server we are exporting from. Run the df command and grep for nfs_share to verify it mounted successfully.

					admin@vm2:~ $ df -Ph | grep nfs_share 10G 32M 10G 1% /nfs_share

Making a persistent NFS share

The NFS share can be made persistent by adding it as an entry to the /etc/fstab file. This will allow the /nfs_share to mount automatically even after rebooting your machine (see image below).

Persistent NFS shares

Photo by admingeek from Infotechys


Congratulations! You now know how to create and export an NFS server in Linux. Was this article helpful to you? If so, leave us a comment below and share!

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