What kind of virtualization is Docker?

technology?

Docker is an operating system-level lightweight virtualization technology that can run multiple independent application containers in a single operating system instance. It creates an isolated user space on the host to run multiple different applications on the same host, and these applications do not interfere with each other and run independently of each other.

Docker is implemented by utilizing a feature called cgroup (control groups) and another feature called namespace in the Linux kernel. Cgroup is a feature of the Linux kernel that is used to limit, isolate, and manage processes and their resources. It can control the usage of resources such as CPU, memory, I/O, and network. Namespace is a feature of the Linux kernel that can isolate various resources in the system, such as process ID, network, file system, etc.

When Docker is running, it will create a new namespace and assign a set of system resources to this namespace. This namespace is isolated and encapsulated, so applications within it cannot see information from other namespaces and cannot access other applications' resources. In Docker, each container has its own file system, network stack, process tree, etc. These are all implemented through namespaces. Therefore, each container is independent of each other and does not affect each other.

Compared with traditional virtualization technology, the advantage of Docker is that it is more lightweight, more flexible, more open, and easier to deploy and manage. Traditional virtualization technology requires the installation of a complete operating system and application environment in a hardware virtual machine, which consumes a lot of resources and time. Docker gets rid of this limitation by sharing the host's operating system kernel. In this way, not only can resources be saved, but also applications can be quickly built and migrated in various aspects such as development, testing, and deployment.

In addition, Docker also supports the portability of containers. Container applications can run on any system that supports Docker container operation without considering system compatibility issues. This means that developers can more freely choose the environment in which their applications are deployed, without having to worry about compatibility issues between different systems.

In general, Docker’s position in virtualization technology is becoming increasingly important. With the rapid development of cloud computing, big data, artificial intelligence and other fields, Docker’s advantages in application deployment and management will become more and more important. have received more and more widespread attention.

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