Distributed file serving architecture system with metadata storage virtualization and data access at the data server connection speed

A program storage readable by one or more computers, the program storage having media tangibly embodying one or more programs of instructions executable by a computer to perform a method for satisfying a request in a distributed file serving architecture with metadata storage virtualization and direct data access, comprising:

• storing metadata associated with data on a data server in memory at a metadata server;
• establishing a file-based remote direct memory access protocol session with a host and a data server;
• receiving a data request at the metadata server from the host through an operations channel established between the host and the metadata server for providing asynchronous communication initiated only by the host;
• controlling virtualization of the data server file system at the metadata server, wherein the controlling is performed by:
• providing data structures containing information about block files represented by logical files on the data server that forms the directory structure:
• and
• providing block data virtualization metadata comprising a mapping of the file system provided by the data server to a metafile system of the metadata server;
• satisfying the data request under the control of the metadata server, said satisfying including:
• providing from the metadata server to the data server, connection and host target buffer information through a back control channel between the metadata server and the data server using the remote direct memory access protocol;
• processing the received connection and host target buffer information;
• using, by said data server, the processed connection and host target buffer information to directly access memory allocated in the host for the data request to satisfy the data request;
• and
• transferring the data requested by said data request from the data server to the host through said file-based remote direct memory access protocol session.

A system, comprising:

• a data server that stores data;
• a host comprising:
• a first memory,
• and instructions, stored on said first memory, for establishing a file-based remote direct memory access protocol session between the host and the data server;
• a metadata server comprising a second memory storing metadata associated with data on the data server;
• wherein said metadata server controls virtualization of the data server file system, wherein the metadata server controls virtualization by:
• providing data structures containing information about block files represented by logical files on the data server that forms the directory structure;
• and
• providing block data virtualization metadata comprising a mapping of the file system provided by the data server to a metafile system of the metadata server;
• wherein said host comprises instructions, stored on said first memory, for establishing an operations channel between the host and the metadata server for providing asynchronous communication initiated only by the host and to provide a data request at the metadata server from the host through the operations channel;
• wherein said metadata server controls the satisfying of the data request, said satisfying including:
• establishing a back control channel between the metadata server and the data server using the remote direct memory access protocol;
• providing from the metadata server to the data server, connection and host target buffer information through the back control channel between the metadata server and the data server using the remote direct memory access protocol;
• processing the received connection and host target buffer information;
• and
• using, by said data server, the processed connection and host target buffer information to directly access memory allocated in the host for the data request to satisfy the data request.