How to Configure Docker to Use a Specific Directory for Storing Data on Ubuntu Server?

To configure Docker to use a specific directory for storing its data on Ubuntu Server, you can follow these steps:

1. Initialize the Disk: You can use parted or fdisk to initialize the disk with a partition table. For example, using fdisk:

   sudo fdisk /dev/sda
   

   Then follow the prompts to create a new partition table (usually GPT for larger disks) and create a new partition.

2. Create a File System: After creating the partition, you need to create a file system on it. For example, to create an ext4 file system:

   sudo mkfs.ext4 /dev/sda1
   

3. Mount the File System: Once you have a file system on the partition, you can mount it to a directory in your file system. You might want to choose a directory under /mnt or /media:

   sudo mkdir /mnt/docker_volume
   sudo mount /dev/sda1 /mnt/docker_volume
   

4. Configure Docker to Use the Directory: You need to modify Docker's configuration file to specify the new data root directory. The configuration file is typically located at /etc/docker/daemon.json. If the file doesn't exist, create it. Add or modify the "data-root" field to point to your desired directory:

   {
     "data-root": "/mnt/docker_volume"
   }
   

   Save the file and exit the text editor.

5. Restart Docker: After modifying the configuration, restart the Docker service to apply the changes:

   sudo systemctl restart docker
   

6. Verify Configuration: You can verify that Docker is using the correct directory by checking the Docker service status and inspecting the Docker configuration:

   • Check Docker service status:

     sudo systemctl status docker
     

     Look for Active: active (running) to confirm that Docker is running.
   • Inspect Docker configuration:

     sudo docker info | grep "Docker Root Dir"
     

     This command should show the directory you specified as the Docker root.