User mode Linux
The so-called User Mode Linux (hereinafter referred to as UML , not to be confused with the Unified Modeling Language , which is also abbreviated as UML ) is a variant of the Linux kernel that allows complete Linux kernels to be used as application processes within operating Linux systems. Execute systems without influencing their configuration and thus stability.
Uses and history
The possible uses are diverse. Network services can run completely isolated from the main system in a UML environment. Often UML is also used to install a so-called " honeypot " with which the security of a computer or network can be tested. Another field of application is testing and debugging software, for example a version of the Linux kernel. The advantage is that the main system is not affected.
Another conceivable area for the use of user mode Linux is driver development for Linux, since debugging a user mode process is easier than with a full-fledged kernel . In addition, a kernel panic (system halt due to a kernel error) with a virtual kernel has no consequences for the actual system, because a new virtual kernel can be started. Finally, it is also interesting to start several virtual kernels at the same time (e.g. for providers of dedicated web servers , who can then offer the customer the Linux distribution of their choice on one and the same system ).
Originally, UML should be called Linux on Linux ( English for Linux on Linux ). However, the idea was discarded to avoid confusion with the acronym LOL .
Since kernel version 2.6.0, UML has been included in the official Linux sources, so that these kernels can be operated as UML processes under a host Linux. If on the host Linux additionally ŠKAS - patch is played, the host kernel to the UML kernel helps with certain administrative tasks, which increases security and performance.
UML is still being actively developed, this particularly applies to the skas extensions.
See also
- VNUML - Uses UML to simulate network scenarios.