Callback hell is a common challenge in asynchronous JavaScript. It occurs when you have multiple nested callbacks, making the code hard to read and maintain. This situation can lead to callback hell, where code becomes difficult to manage and understand.

In JavaScript, the "===" operator, known as the triple equals operator, is used to check for equality without considering the data types of the operands. It ensures both the value and the type of the operands are identical.

The dmesg command would help you determine if Linux has automatically loaded a driver for the new device. dmesg displays kernel messages, and you can look for entries related to the device to see if a driver has been loaded or if there are any issues with it.

The /dev directory in Linux contains device nodes and is crucial for the system's interaction with hardware. Device nodes represent physical and virtual devices, allowing the system to communicate with and control hardware components.

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.

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.

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 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.

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.

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.

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.

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.