Fiber channel topological structure and method including structure and method for raid devices and controllers

A storage system comprising:

• a plurality of disk drives, each said disk drive having a normally active port and a normally inactive port;
• at least one controller for controlling communication with said plurality of disk drives via said normally active ports and under a predetermined condition via said normally inactive ports;
• a plurality of communication channels extending between and coupling said at least one controller and said normally active and said normally inactive ports of said plurality of disk drives;
• and
• said plurality of communication channels arranged in a tube topology and coupling said plurality of disk drives to said controller so that in the event that one of said plurality of communications channels fails, disk access loading is evenly and automatically redistributed between non-failed ones of said plurality of communications channels.

A storage system comprising:

• a plurality of dual-ported storage devices, each said dual-ported storage device having a first port and a second port;
• a controller having a first plurality of primary controller ports and at least one secondary controller port, said first plurality of primary controller ports having at least three primary controller ports including a first Fiber channel port, a second Fiber channel port and a third Fiber channel port, and said at least one secondary controller port including a secondary Fibre channel port;
• each said primary controller port coupled to said first ports of at least two of said plurality of dual-ported storage devices to form a plurality of primary communications channel loops;
• said secondary controller ports coupled to said second port of each of said plurality of dual-ported storage devices to form a secondary communications channel loop;
• and
• each of said plurality of dual-ported storage devices being coupled to said controller by a first communication channel extending from said first port to at least one of said first plurality of primary controller ports, and by a second communication channel extending from said second port to said secondary Fiber channel port.

A storage system having failed communication channel protection, said storage system comprising:

• a level 4 RAID system having first, second, and third data disk drives for storing data and a fourth parity disk drive for storing parity of the data stored on said first, second, and third data disk drives;
• said first, second, and third data disk drives, and fourth parity disk drive striped across different channels;
• a controller having a plurality of channels, each said channel being coupled to one normally active-port of one of said disk drives and to one normally-inactive ports on a different one of said disk drives;
• each said disk drive being accessible during normal operation through said normally-active ports and being accessible through said normally-inactive ports in the event that one of said channels or one of said ports becomes inoperative;
• and
• each said first, second third, and fourth disks remaining accessible via its respective normally-inactive port and said in the event that one of said channels coupling each said disk drive to said controller fails.

A multiple-RAID3 storage system loop topology interconnect structure comprising:

• first (261), second (262), third (263), and fourth (264) Fiber channels coupled respectively to first (265), second (266), third (267), and fourth (268) RAID controller Fibre ports;
• each said fibre channel being coupled to a normally active disk drive port of a first set of RAID3 disks (271), a second set of RAID3 disks (272), a third set of RAID3 disks (273), and a fourth set of RAID3 disks (274), respectively;
• each of the fiber channels is also coupled to a normally inactive disk drive port of a set of RAID3 disk drives different from said first, second, third, and fourth sets of RAID3 disks in wrap-around fashion such that first fibre channel (261) is also coupled to said second RAID3 (272), second fibre channel (262) is also connected to said third RAID3 set (273), third fibre channel (263) is also connected to said fourth RAID3 set (274), and fourth Fibre channel (264) is also connected to said first RAID3 set (271);
• and
• each said RAID3 disk set (271, 272, 273, 274) having said normally active set of disk drive ports coupled to one Fibre channel and said normally inactive disk drive ports coupled to a different Fibre channel.

A multiple-RAID5 storage system loop topology interconnect structure comprising:

• first (281), second (282), third (283), and fourth (284) Fiber channels coupled respectively to first (285), second (286), third (287), and fourth (288) RAID controller Fibre ports;
• each said fibre channel being coupled to a normally active disk drive port of a first set of RAID5 disks (291), a second set of RAID5 disks (292), a third set of RAID5 disks (293), and a fourth set of RAID5 disks (294) respectively;
• and
• said interconnection topology also providing a connection of each of said fiber channels to the normally-inactive disk drive port of a different RAID5 disk drive set in wrap-around fashion wherein a common Fibre channel connects across a plurality of disk drives associated with different RAID5 sets.

A mixed RAID3 and RAID5 storage system loop topology interconnect structure comprising:

• a RAID3 disk array storage subsystem;
• a RAID5 disk array storage subsystem;
• a first Fiber channel loop coupled to normally-active ports of said RAID3 storage subsystem and to normally-inactive ports of said RAID5 storage subsystem;
• a second Fiber channel loop coupled to normally-active ports of said RAID5 storage subsystem and to normally-inactive ports of said RAID3 storage subsystem;
• and
• said first Fibre loop for said RAID3 storage subsystem being the back-up communications channel for said RAID5 storage subsystem, and said second Fibre loop for said RAID5 storage subsystem being the back-up communications channel for said RAID3 storage subsystem.