Anna is a XTAO project branched from CEPH distributed storage. CEPH is a nice opensource project for unified distributed storage which is supposed to support block, file and object storage access. Unfortuntely, there is a gap between an opensource project and a real enterprise level storage system. Especially, File system of CEPH is a fragile and is hard to be treated as a serious enterprise storage system. XTAO dedicated a team and took several years to complete the filesystem and object storage for CEPH. And XTAO invented a mechanism for CEPH to seamlessly integrate filesystem/object store with unstructural data managment system.