Integrated-circuit implementation of a storage-shelf router and a path controller card for combined use in high-availability mass-storage-device shelves that may be incorporated within disk arrays, and a storage-shelf-interface tunneling method and system

• US 20040148460A1
• Filed: 11/04/2003
• Published: 07/29/2004
• Est. Priority Date: 01/13/2003
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Sierra Logic (Broadcom, Inc.)
• Inventors: Kompella, Murthy, Wakeley, Matthew Paul, Steinmetz, Joseph Harold
• Granted Patent: US 7,167,929 B2
• Time in Patent Office: Days
• US Class Current: 711/114
• CPC Class Codes: G06F 11/201 between storage system components
• CPC Class Codes: G06F 11/2089 Redundant storage control functionality
• CPC Class Codes: G06F 2003/0697 device management, e.g. handlers, drivers, I/O schedulers
• CPC Class Codes: G06F 3/0601 Interfaces specially adapted for storage systems
• CPC Class Codes: G06F 3/0607 by facilitating the process of upgrading existing storage systems, e.g. for improving compatibility between host and storage device
• CPC Class Codes: G06F 3/0611 in relation to response time
• CPC Class Codes: G06F 3/0617 in relation to availability
• CPC Class Codes: G06F 3/0635 by changing the path, e.g. traffic rerouting, path reconfiguration
• CPC Class Codes: G06F 3/064 Management of blocks
• CPC Class Codes: G06F 3/0658 Controller construction arrangements
• CPC Class Codes: G06F 3/0659 Command handling arrangements, e.g. command buffers, queues, command scheduling
• CPC Class Codes: G06F 3/0661 Format or protocol conversion arrangements
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD
• CPC Class Codes: H04L 12/4633 Interconnection of networks using encapsulation techniques, e.g. tunneling
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]
• CPC Class Codes: H04L 69/08 Protocols for interworking; Protocol conversion
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

An integrated circuit implementing a storage-shelf router, used in combination with path controller cards and optionally with other storage-shelf routers, to interconnect SATA disks within a storage shelf or disk array to a high-bandwidth communications medium, such as an FC arbitrated loop. Various embodiments of the present invention provide a tunneling mechanism through the storage-shelf interface provided by one or more storage-shelf routers within a storage shelf to enable external processing entities to directly access various components within the storage shelf. In one embodiment of the present invention, a WRITE-BUFFER command and a READ-BUFFER command are added to the command interface supported by storage-shelf router. These commands are exchanged via the FCP protocol over the fiber channel in the same manner that SCSI commands are packaged within the FCP protocol. In certain cases, the information packaged within the WRITE-BUFFER and READ-BUFFER commands is directly exchanged with internal disk drives. In other cases, the information is extracted and written to various data structures maintained within internal components of the storage shelf. The WRITE-BUFFER and READ-BUFFER commands essential provide a breach or tunnel in the high-availability storage-shelf virtual interface provided by one or more storage-shelf routers within a storage shelf, allowing an external processing entity to exchange information through the tunnel without intervention by, but facilitated and supported by, the one or more storage-shelf routers within the high-availability storage shelf.

Claims

1. A storage-shelf-router-interface tunnel comprising:

an external processing entity interconnected with a storage shelf by a first communications medium using commands of a first protocol;

mass-storage devices within the storage shelf that may be accessed by a mass-storage-device protocol through a second communications medium;

a storage-shelf router that provides a virtual interface to mass-storage devices within the storage shelf to external processing entities, translating first-protocol commands received from the first communications medium to mass-storage-device protocol commands sent to mass-storage devices through the second communications medium, and that also provides for direct access by the external processing entity to the mass-storage devices by unpackaging mass-storage-device-protocol commands from a particular type of first-protocol command frame received through the first communications medium and directing the unpackaged mass-storage-device-protocol commands through the second communications medium, without translation, to the mass-storage devices.

2. The storage-shelf-router-interface tunnel of claim 1 wherein the storage router receives responses to the unpackaged mass-storage-device-protocol commands directed to the mass-storage devices from the mass-storage devices through the second communications medium, packages the responses into a particular type of first-protocol frame, and returns the packaged responses through the first communications medium to the external processing entity.

3. The storage-shelf router of claim 1 further including providing, to the external processing entity, access to storage shelf data structures and storage-router firmware through a particular type of first-protocol command frame and response frame.

4. The storage-shelf router of claim 1 wherein the first communications medium is a fibre channel communications link and wherein the second communications medium is a serial or parallel communications medium interconnecting the storage-shelf router to a path controller card interfaced to an ATA disk drive.

5. The storage-shelf router of claim 1 wherein the first communications medium is a fibre channel communications link and wherein the second communications medium is a serial or parallel communications medium interconnecting the storage-shelf router to an ATA disk drive.

6. The storage-shelf router of claim 1 wherein the particular type of first-protocol command frame received through the first communications medium is one of a WRITE_BUFFER command or a READ_BUFFER command packaged within an FCP_CMND frame.

7. The storage-shelf router of claim 1 wherein, in addition to unpackaging mass-storage-device-protocol commands from a particular type of first-protocol command frame received through the first communications medium and directing the unpackaged mass-storage-device-protocol commands through the second communications medium, without translation, to the mass-storage devices, the storage-shelf router unpackages control directives from the particular type of first-protocol command frame received through the first communications medium and directs corresponding control operations to storage-shelf components, including mass-storage devices.

9. The storage-shelf router of claim 1 wherein, in addition to unpackaging mass-storage-device-protocol commands from a particular type of first-protocol command frame received through the first communications medium and directing the unpackaged mass-storage-device-protocol commands through the second communications medium, without translation, to the mass-storage devices, the storage-shelf router unpackages access directives from the particular type of first-protocol command frame received through the first communications medium and accesses specified storage-shelf components, including mass-storage devices.

8. The storage-shelf router of claim 8 wherein the control directives include power-on, power-off, and reset control directives.

10. The storage-shelf router of claim 8 wherein the access directives include:

writing all or a portion of the contents of a data structure stored in storage-shelf-router flash memory;

writing all or a portion of the contents of a data structure stored in path-controller-card flash memory;

writing all or a portion of the contents of a data structure stored in special sectors within a mass-storage device;

writing all or a portion of the storage-shelf firmware stored in storage-shelf-router flash memory;

writing all or a portion of the path-controller-card firmware stored in path-controller-card flash memory;

reading all or a portion of the contents of a data structure stored in storage-shelf-router flash memory;

reading all or a portion of the contents of a data structure stored in path-controller-card flash memory;

reading all or a portion of the contents of a data structure stored in special sectors within a mass-storage device;

reading all or a portion of the storage-shelf firmware stored in storage-shelf-router flash memory; and

reading all or a portion of the path-controller-card firmware stored in path-controller-card flash memory.

11. A method for providing direct access by an external processing entity to mass-storage devices within a storage shelf that are virtualized by a storage-shelf router within the storage shelf through a storage-shelf-router interface, the method comprising:

in a first communications protocol by which the external processing entity accesses virtual mass-storage devices through the storage-shelf-router interface, identifying a command frame that can be used to supplement the first-communications protocol with tunneling commands;

inserting a native mass-storage-device command into the identified tunneling command frame and passing the native mass-storage-device command through the tunneling command to the storage-shelf router;

receiving the tunneling command by the storage-router;

extracting the native mass-storage-device command from the tunneling command and forwarding the tunneling command to a mass-storage device within the storage shelf by a second communications medium.

12. The method of claim 11 further including:

receiving, by the storage-shelf router, a response to the forwarded native mass-storage-device command through the second communications medium, inserting the response into a first-protocol response frame, and returning the response to the external processing entity.

13. The method of claim 11 wherein the first communications medium is a fibre channel communications link and wherein the second communications medium is a serial or parallel communications medium interconnecting the storage-shelf router to a path controller card interfaced to an ATA disk drive.

14. The method of claim 11 wherein the identified first-protocol command frame is one of a WRITE_BUFFER command or a READ_BUFFER command packaged within an FCP_CMND frame.

15. A storage-shelf router comprising:

logic for receiving first-protocol commands through a first communications medium directed to virtual mass-storage devices;

logic for translating the received commands into native mass-storage-device commands;

logic for transmitting the translated, native mass storage commands to mass-storage devices through a second communications medium; and

logic for receiving native mass-storage-device commands packaged within selected first-protocol commands and forwarding the native mass-storage-device commands, untranslated, to mass-storage devices.

16. The storage-shelf router of claim 15 further including:

logic for receiving responses to translated mass-storage commands from mass-storage devices through the second communications medium, translating the responses into first-protocol responses, and forwarding the first-protocol responses to the first communications medium; and

logic for receiving responses to untranslated mass-storage commands from mass-storage devices through the second communications medium, packaging the responses, untranslated, into first-protocol responses, and forwarding the untranslated responses to untranslated mass-storage commands packaged within first-protocol responses to the first communications medium.