Operating Systems

2024/10/06

• namespaces

- [Edo](//github.com/EdoardoLaGreca/9knowledge)	has a much better explanation
- can be thought of as certain _perspectives_ of a file system. 

A name space can be thought as a certain perspective of the file system. Disks store some persistent files those being just just data in a memory device. Every file in the disk has a certain path, which informs about the location of the file. Unless you change the path of a file, or create or delete a file somewhere, the paths are fixed. However, thanks to the bind and mount operations, one can temporarily change the file system and model it at will. You can tell the operating system to mirror the changes to a file or directory to another file or directory (bind), or to add an remote file system to the local one and make it look local (mount).

One may read somewhere that name spaces are "unique to each process" or that they are "per-process name spaces". Both expressions refer to the same fact, which is that each name space is held by only one process, regardless of whether two name spaces are identical. A name space is not just a certain perspective, but an instance of that perspective, associated to a process.

• userland

- all code running outside an OS' kernel. Usually referring to vorious programs and libraries that the OS uses to interact with the kernel