System and method for communications in serial attached SCSI storage network

• US 20050108452A1
• Filed: 11/13/2003
• Published: 05/19/2005
• Est. Priority Date: 11/13/2003
• Status: Active Grant

• Current Assignee: Dell Products LP (Dell Technologies Inc.)
• Original Assignee: Dell Products LP (Dell Technologies Inc.)
• Inventors: Loffink, John S.
• Granted Patent: US 7,058,749 B2
• Time in Patent Office: Days
• US Class Current: 710/74
• 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 3/0658 Controller construction arrangements
• CPC Class Codes: G06F 3/0661 Format or protocol conversion arrangements
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]

Abstract

A network topology and bridge device is disclosed for a Serial Attached SCSI storage network. The bridge devices is coupled between each Serial ATA drive of the network and the remainder of the elements of the storage network and translates storage transactions between the Serial ATA drive and the remainder of the Serial Attached SCSI storage network.

Claims

1. A storage network, comprising:

multiple SCSI controllers;

an expander device coupled to each controller;

at least one bridge device, wherein each bridge device is coupled to a plurality of expander devices; and

at least one Serial ATA drive, wherein each Serial ATA drive is coupled to an output port of the bridge device.

2. The storage network of claim 1, wherein the bridge device is operable to translate serial data communications from the Serial Attached SCSI protocol to the Serial ATA protocol.

3. The storage network of claim 2, wherein the serial data communications in the Serial Attached SCSI protocol include serial data formatted according to the Serial ATA Tunneling protocol.

4. The storage network of claim 2, wherein each bridge device is operable to arbitrate between data streams such that the Serial ATA drive coupled to the bridge drive receives, at any one time, only one data stream.

5. The storage network of claim 2, wherein each bridge device is operable to route communications from the Serial ATA drive to an expander device that is associated with the SCSI controller to whom the communication from the Serial ATA drive is directed.

6. The storage network of claim 2,

wherein the serial data communications in the Serial Attached SCSI protocol include serial data formatted according to the Serial ATA Tunneling protocol;

and

wherein each bridge device is operable to arbitrate between data streams such that the Serial ATA drive coupled to the bridge drive receives, at any one time, only one data stream.

7. The storage network of claim 2,

wherein the serial data communications in the Serial Attached SCSI protocol include serial data formatted according to the Serial ATA Tunneling protocol;

wherein each bridge device is operable to arbitrate between data streams such that the Serial ATA drive coupled to the bridge drive receives, at any one time, only one data stream;

wherein each bridge device is operable to arbitrate between data streams such that the Serial ATA drive coupled to the bridge drive receives, at any one time, only one data stream; and

wherein each bridge device is operable to route communications from the Serial ATA drive to an expander device that is associated with the SCSI controller to whom the communication from the Serial ATA drive is directed.

8. The storage network of claim 1, wherein each bridge device is associated with a single Serial ATA drive.

9. A method for translating data directed data to a Serial ATA drive in a Serial Attached SCSI storage network, comprising the steps of:

providing a bridge device interposed at the input port of the serial ATA drive, the bridge device comprising;

a plurality of input ports coupled to other elements of the storage network and operable to receive data in Serial Attached SCSI protocol;

a translation node operable to translate the data from the Serial Attached SCSI protocol to the Serial ATA protocol; and

an output port coupled to the Serial ATA drive.

10. The method for translating data directed to a Serial ATA drive in a Serial Attached SCSI network of claim 9, wherein the data in the Serial Attached SCSI protocol is transmitted in the Serial ATA Tunneling Protocol.

11. The method for translating data directed to a Serial ATA drive in a Serial Attached SCSI network of claim 9, wherein the bridge device is coupled between multiple expander devices and a Serial ATA drive such that each input port is coupled to an expander device.

12. The method for translating data directed to a Serial ATA drive in a Serial Attached SCSI network of claim 11, wherein the provided bridge devices further comprises a arbiter node operable to manage the flow of data in the Serial Attached SCSI protocol to the translation node.

13. The method for translating data directed to a Serial ATA drive in a Serial Attached SCSI network of claim 11, wherein the arbiter node is operable to route communications from the Serial ATA drive coupled to the output node of the bridge device to an expander device associated with to SCSI controller to whom the communication is directed.

14. A bridge device for coupling elements of a Serial Attached SCSI network to a Serial ATA drive, comprising:

multiple input ports, each operable to receive communications routed through separate expander devices;

an output port coupled to a Serial ATA drive; and

and a translation node operable to translate serial data in the Serial Attached SCSI protocol to serial data in the Serial ATA protocol.

15. The bridge device of claim 14, wherein the bridge device is associated with a single Serial ATA drive.

16. The bridge device of claim 15,

wherein the bridge device is coupled to at least two expander devices;

and

wherein each expander device is associated with a single SCSI controller.

17. The bridge device of claim 16, further comprising an arbiter for managing flow of data from each of the input ports such that only a single stream of serial data is being translated at any one time at the translation node.

18. The bridge device of claim 16, further comprising an arbiter for managing the flow of serial data from the Serial ATA drive such that data is directed from the translation node to an input port associated with an expander device that is operable to route the serial data to the SCSI controller to whom the serial data is directed.

19. The bridge device of claim 16, further comprising an arbiter operable to,

manage the flow of data from each of the input ports such that only a single stream of serial data is being translated at any one time at the translation node;

and

manage the flow of serial data from the Serial ATA drive such that data is directed from the translation node to an input port associated with an expander device that is operable to route the serial data to the SCSI controller to whom the serial data is directed.

20. The bridge device of claim 14, wherein the translation node is operable to translate data in the Serial ATA Tunneling Protocol.