BlueStore is a Ceph object store that's primarily designed to address the limitations of filestore, which, prior to the Luminous release, was the default object store. Initially, a new object store named NewStore was being developed to replace filestore. NewStore was a combination of RocksDB, a key–value store that stored metadata and a standard Portable Operating System Interface (POSIX) filesystem for the actual objects. However, it quickly became apparent that using a POSIX filesystem introduced high overheads and restrictions, which was one of the key reasons for trying to move away from using filestore in the first place.
Hence, BlueStore was born. Using raw block devices in combination with RocksDB, a number of problems that had stunted NewStore were solved. The name BlueStore was a reflection of the combination of the words Block and NewStore...
