Chimera is a library providing a hierarchical name space with associated meta data. Where pools in dCache store the content of files, Chimera stores the names and meta data of those files. Chimera itself stores the data in a relational database.

Chimera is the replacement and successor of PNFS, the original dCache name service. In any distributed storage system the nameserver can be a bottleneck. The primary way of achieving more performance was allowing access to nameserver (Chimera) from dCache components through an API, as opposed to requiring all communication through the filesystem interface as is the case with PNFS. Chimera also provides a mountable filesystem which satisfies the NFS 4.1 specification.The NFS 4.1 specification provides for mounting distributed storage in such a way that ordinary unix commands (cp, ls, etc) may work without modification.