Data storage system having separate data transfer section and message network with bus arbitration

A data storage system for transferring data between a host computer/server and a bank of disks drives through a system interface, such system interface comprising:

• a plurality of first directors coupled to host computer/server;
• a plurality of second directors coupled to the bank of disk drives;
• a data transfer section having a cache memory, such cache memory being coupled to the plurality of first and second directors;
• a messaging network, operative independently of the data transfer section, coupled to the plurality of first directors and the plurality of second directors;
• and
• wherein the first and second directors control data transfer between the host computer and the bank of disk drives in response to messages passing between the first directors and the second directors through the messaging network to facilitate the data transfer between host computer/server and the bank of disk drives with such data passing through the cache memory in the data transfer section;
• wherein each one of the first directors includes:
• a data pipe coupled between an input of such one of the first directors and the cache memory;
• a microprocessor;
• a controller;
• a common bus, such bus interconnecting the data pipe, the microprocessor, and the controller;
• and wherein
• the controller controls the transfer of the messages between the message network and such one of the first directors and the data between the input of such one of the first directors and the cache memory.

A method of operating a system interface having a plurality of first directors, a plurality of second directors and a data transfer section having a cache memory, such cache memory being coupled to the plurality of first and second directors, such method comprising:

• providing a messaging network, operative independently of the data transfer section, coupled to the plurality of first directors and the plurality of second directors to control data transfer between the first directors and the second directors in response to messages passing between the first directors and the second directors through the messaging network to facilitate data transfer between first directors and the second directors with such data passing through the cache memory in the data transfer section;
• and providing each one of the first directors with:
• a data pipe coupled between an input of such one of the first directors and the cache memory;
• a microprocessor;
• a controller;
• a common bus, such bus interconnecting the data pipe, the microprocessor, and the controller;
• and wherein
• the controller controls the transfer of the messages between the message network and such one of the first directors and the data between the input of such one of the first directors and the cache memory.