Xen Project Developer Summit

"We have been developing a new storage system designed specifically for unikernels such as MirageOS that run in a stub-domain environment. In this mode, domains only have access to raw device rings such as Blkfront, and no ""real"" filesystem.

Our new Irminsule filesystem builds on the principles of Git to give every unikernel the same primitives as a distributed version control systems. Unikernels can attach to shared block devices and pull, merge and push trees of blobs with other unikernels. Conflicts are resolved at the application level via merge functions defined specifically for the usecase at hand, and consistency models can be tailored to reduce the conventional overheads of general purpose filesystems.

Our use is to rewrite OXenstored, resulting in all transactions being reflected as a Git tree, making debugging complex deployments much more tractable and distributed."