Shared storage is a critical component in many Linux environments as it allows multiple systems to access and share data simultaneously. It is especially useful in scenarios where high availability, scalability, and data redundancy are required. In Linux, shared storage can be achieved using various technologies such as Network File System (NFS), Storage Area Network (SAN), and Distributed File System (DFS). These technologies provide a centralized storage solution that can be accessed by multiple Linux systems over a network.

NFS is a popular choice for shared storage in Linux. It allows a Linux system to share directories and files with other Linux systems over a network. NFS uses the client-server model, where the server exports directories that can be mounted by clients. The clients can then access and modify the shared files as if they were local. NFS provides a simple and efficient way to share storage between Linux systems.

To set up shared storage using NFS in Linux, follow these steps:

1. Install the NFS server package on the system that will act as the server:

   sudo apt-get install nfs-kernel-server

2. Create a directory that will be shared with other systems:

   sudo mkdir /shared

3. Configure the NFS server by editing the exports file:

   sudo nano /etc/exports

Add the following line to the file to allow access to the shared directory from a specific client:

/shared client_IP(rw,sync,no_root_squash)

Replace client_IP with the IP address of the client system that will access the shared storage.

4. Save the file and exit the editor.

5. Export the shared directory by running the following command:

   sudo exportfs -a

6. Start the NFS server:

   sudo systemctl start nfs-kernel-server

Now the shared storage is set up on the server. To access the shared storage from a client system, follow these steps:

1. Install the NFS client package on the client system:

   sudo apt-get install nfs-common

2. Create a directory on the client system to mount the shared storage:

   sudo mkdir /mnt/shared

3. Mount the shared storage by running the following command:

   sudo mount server_IP:/shared /mnt/shared

   Replace server_IP with the IP address of the NFS server.

4. Access the shared storage by navigating to the mounted directory:

   cd /mnt/shared

You can now read, write, and modify files in the shared storage as if they were local.