Does Github auto backup our projects into globally spread mirrors, like SourceForge?

问题

I am talking about this:
"SourceForge.net maintains a geographically-distributed network of mirror servers, which receive copies of the files and dispense them to users."

So, does github has the same automatically mirrored backup of our projects and files? I am having big trouble trying to find that information.

回答1:

Yes, it is called DGit for Distributed Git:

As many readers already know, Git itself is distributed—any copy of a Git repository contains every file, branch, and commit in the project’s entire history.
DGit uses this property of Git to keep three copies of every repository, on three different servers. The design of DGit keeps repositories fully available without interruption even if one of those servers goes down.

DGit automatically selects the servers to host each repository, keeps those replicas in sync, and picks the best server to handle each incoming read request. Writes are synchronously streamed to all three replicas and are only committed if at least two replicas confirm success.

GitHub now stores repositories in a cluster called github-dfs—dfs is short for “DGit file server.” The repositories are stored on local disks on these file servers and are served up by Git and libgit2. The clients of this cluster include the web front end and the proxies that speak to users’ Git clients.

回答2:

Yes in a way. Git is a distributed source control system. But only if others are using the repository. Some projects will have hundreds of offsite replications. Others sadly very few.

But these off site copies are not available to you directly

来源：https://stackoverflow.com/questions/37851239/does-github-auto-backup-our-projects-into-globally-spread-mirrors-like-sourcefo