Ceph is a massively scalable, open source, distributed storage system. It is comprised of an object store, block store, and a POSIX-compliant distributed file system. The system is described in technical detail in Ceph: A Scalable, High-Performance Distributed File System from the OSDI 2006 conference.
The Ceph on Arm working group is a group of individuals and organizations working to advance the state-of-the-art for Ceph running on Arm devices. They meet regularly on the first Tuesday of each month to discuss the state of the art and advances and issues.