When debugging a shell script, you can use the -x option with the bash command to enable debugging output. This option displays each command as it is executed, making it useful for identifying issues and understanding the script's execution flow.

The primary purpose of the df command is to display disk space usage on a Linux system. It provides information about the disk space used and available on various mounted filesystems. This command is useful for monitoring disk space to prevent overflows.

Btrfs (B-Tree File System) is designed to offer advanced features such as data pooling, snapshots, and checksums. It is a next-generation file system that provides data integrity and efficient storage management. Btrfs is often used in modern Linux distributions for its advanced capabilities.

KVM stands for Kernel-based Virtual Machine. It is a Linux kernel module that enables hardware-assisted virtualization, allowing you to run multiple virtual machines on a single host.

Kubernetes is used for orchestrating multiple Docker containers. It's a powerful container orchestration platform that automates the deployment, scaling, and management of containerized applications.

The sudo command in Linux allows users to execute commands as another user, typically the superuser (root). It provides a fine-grained control mechanism for delegating administrative privileges while maintaining an audit trail of who executed which commands with elevated privileges.

When working with Docker, the Dockerfile is used to define and configure the container's environment. This includes specifying the base image, installing software, setting environment variables, and other container-specific configurations.

You can temporarily add the break command to halt the script's execution at a specific point during debugging. This allows you to inspect variables, control flow, and identify the source of the error. Once the debugging is complete, you can remove the break statement to resume normal script execution.

When working with file permissions, the chmod command is used to modify the special permissions like setuid, setgid, and the sticky bit. These special permissions can change the behavior of files and directories, and chmod is used to set or remove them.

The primary purpose of the netstat command is to display network statistics and connections. It provides valuable information about network interfaces, routing tables, and active network connections. It's a crucial tool for network troubleshooting and monitoring.