On the surface, mirroring with Git is really easy. You just do “git clone --mirror” on the remote system and after it’s done, you have a full mirror of the repository. However, that’s just the easy first step. The real difficulty is keeping that mirror updated so it receives the commits from the master on a regular basis. The tool Linux Foundation sysadmins developed, called Grokmirror makes it easy to reproduce all of kernel.org repositories and keep them up-to-date -- easy not just for us, but also for everyone who is interested in running such a mirror on their end.