dockerd:tldr:961a5

The command dockerd --pidfile ${path-to-pid_file} is used to start the Docker daemon with a specified process ID (PID) file. Here's a breakdown of the command elements:

• dockerd: This is the command to start the Docker daemon, which is responsible for managing Docker containers and images on the system.
• --pidfile: This is an option used to specify the path to the PID file where the Docker daemon will write its process ID.
• ${path-to-pid_file}: This is a placeholder that needs to be replaced with the actual path where you want the PID file to be created. The PID file typically has a .pid extension and contains the process ID of the running Docker daemon.

When the Docker daemon starts with the --pidfile option, it creates a file at the specified path and writes the process ID of the daemon into that file. This PID file can be useful for various purposes, such as monitoring, process management, or checking the status of the Docker daemon.

Note: Make sure to replace ${path-to-pid_file} with the desired file path on your system before running the command.