What is NFS #

NFS stands for Network File System. It’s a distributed file system protocol that allows a user on a client computer to access files over a network as if they were stored locally. NFS enables sharing files and directories among multiple computers in a network.

How NFS work? #

Server: A computer that exports its directories or files to be shared with other computers on the network is called an NFS server.
Client: A computer that accesses shared files or directories from the NFS server is called an NFS client.
Exporting: On the NFS server, administrators define which directories or files are available for sharing with other computers. This process is known as exporting.
Mounting: On the NFS client, users mount the shared directories from the NFS server onto their local file system. Once mounted, these shared directories can be accessed and manipulated like local files and directories.
Access Control: Administrators can control access to shared directories by specifying which clients are allowed to access them and what level of access they have (read-only or read-write).

NFS is commonly used in Unix and Linux environments for sharing files and directories among servers, workstations, and other networked devices. It simplifies data sharing and collaboration in networked environments and is often preferred for its simplicity and efficiency.

Use Cases of NFS in load balancers #

In disaster recovery scenarios for load balancer servers, NFS (Network File System) can be utilized in several ways to ensure high availability and data consistency. Here’s how NFS can be used specifically for disaster recovery in load balancer setups:

Shared Configuration: Load balancers often require consistent configuration across multiple instances to ensure uniform behavior and efficient traffic distribution. NFS can be used to store configuration files centrally, allowing all load balancer nodes to access and synchronize their configurations from a single source. This ensures that changes made to the configuration are immediately available to all nodes, simplifying management and ensuring consistency.

Session Persistence: In certain scenarios, load balancers need to maintain session persistence, ensuring that subsequent requests from the same client are directed to the same backend server. NFS can be used to store session data shared among load balancer nodes. By storing session information in a shared NFS directory, all nodes can access and update session data as needed, ensuring seamless session persistence across the load balancer cluster.

Dynamic Content Caching: Load balancers often employ caching mechanisms to improve performance by serving cached content directly to clients without forwarding requests to backend servers. NFS can be used to store cached content shared among load balancer nodes. By storing cached content in a shared NFS directory, all nodes can access and serve cached content, improving performance and reducing load on backend servers.

SSL/TLS Certificate Management: Load balancers often terminate SSL/TLS connections and require SSL/TLS certificates for secure communication with clients. NFS can be used to store SSL/TLS certificates centrally, allowing all load balancer nodes to access and use the same set of certificates. This simplifies certificate management and ensures consistent encryption across the load balancer cluster.

Logging and Monitoring: Load balancers generate log files and monitoring data that are critical for troubleshooting, performance analysis, and security auditing. NFS can be used to store log files and monitoring data centrally, allowing all nodes to write log entries and monitoring data to a shared NFS directory. This centralizes logging and monitoring data, making it easier to analyze and manage, and ensuring that data is not lost if individual nodes fail.

By leveraging NFS for shared storage, Linux load balancers can achieve improved scalability, reliability, and manageability in production environments, ensuring consistent performance and high availability for distributed applications and services.

How to setup NFS in RELIANOID load balancers #

To set up NFS on a RELIANOID Load Balancers Enterprise version v6, based on Debian Linux Buster, follow these steps. Note that these packages are not included by default in RELIANOID repositories, so external packages are needed to be installed.

1. Create a Directory for Package Storage. Log in to your load balancer and create a directory to store the downloaded packages:

root@ee-noid:~# mkdir -p /opt/nfs

2. Download NFS and Dependencies. Download the following Debian packages:
    nfs-common
    rpcbind
    libevent-2.1-6
    libnfsidmap2
    keyutils
    libtirpc3
    libtirpc-common

Upload those packages in the load balancer at /opt/nfs .

3. Install Packages. Install the downloaded packages using the dpkg command:

root@ee-noid:~# dpkg -i /opt/nfs/*.deb

4. Remove Downloaded Packages. Remove the downloaded Debian packages to clean up disk space:

root@ee-noid:~# rm -rf /opt/nfs

5. Mount NFS Share. Mount the NFS share using the mount command:

root@ee-noid:~# mkdir -p /mnt/<mount_point>
root@ee-noid:~# mount <nfs_server>:/<nfs_folder> /mnt/<mount_point>

Replace <nfs_server> with the NFS server’s IP address or hostname, <nfs_folder> with the shared folder on the NFS server, and <mount_point> with the desired mount point on the load balancer.

5. Automatically Mount and Unmount NFS Share. To automatically mount the NFS share on boot, you can add an entry to the /etc/fstab file:

<nfs_server>:/<nfs_folder> /mnt/<mount_point> nfs defaults 0 0

These steps will set up NFS on your RELIANOID Load Balancers Enterprise v6 running Debian Linux Buster, allowing you to share files and directories across your network. Additionally, the automatic mount and unmount configurations ensure that the NFS share is managed seamlessly during system boot and shutdown.