Techniques for accessing devices through a set of serial buses automatically setting unique enclosure addresses and detecting non-unique enclosure addresses upon initialization

• US 7,216,188 B2
• Filed: 03/29/2003
• Issued: 05/08/2007
• Est. Priority Date: 03/29/2003
• Status: Active Grant

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: EMC Corporation (Dell Technologies Inc.)
• Inventors: Sardella, Steven D., Reid, Geoffrey A.
• Primary Examiner(s): PEYTON, TAMMARA R
• Application Number:
  US10/402,334
• Publication Number:
  US 20040190545A1
• Time in Patent Office: 1,501 Days
• Field of Search: 710/72, 710/74, 710/9, 714/4, 714/48, 714/25, 711/112, 711/144, 709/224, 709/245, 709/228, 709/22
• US Class Current: 710/74
• CPC Class Codes: G06F 3/0605 by facilitating the interaction with a user or administrator
• CPC Class Codes: G06F 3/0632 by initialisation or re-initialisation of storage systems
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD
• CPC Class Codes: H04L 61/5038 for local use, e.g. in LAN or USB networks, or in a controller area network [CAN]

Abstract

In a system including multiple enclosures, unique enclosure addresses can be set automatically via software. The enclosure addresses may be stored in non-volatile memory within the enclosures. In a storage system, several enclosures contain several disk drives, wherein each disk drive requires a unique device address related to the enclosure in which it resides. A unique address is automatically assigned via software to each enclosure.

Claims

1. Apparatus comprising:

a plurality of enclosures, each enclosure containing a plurality of devices, each enclosure initially having a non-unique enclosure address associated with itself;

logic for automatically setting a unique enclosure address for each enclosure for use in addressing devices in the enclosure;

wherein each non-unique enclosure address indicates that the corresponding enclosure is not initialized; and

the logic is configured to automatically set the unique enclosure address for each enclosure in response to detecting the non-unique enclosure address upon initialization of the enclosures.

19. The apparatus of claim 1, wherein the logic is configured to:

send a poll message to the plurality of enclosures;

receive a response message in response to the poll message, the response message including enclosure addresses for each enclosure of the plurality of enclosures;

ascertain whether the enclosure addresses are unique for each enclosure of the plurality of enclosures;

ascertain a position of an enclosure that has a non-unique address when the enclosure addresses are not unique; and

send an index message to the enclosure at the ascertained position, the index message including a unique enclosure address for the enclosure at the ascertained position.

20. The apparatus of claim 19, wherein the index message includes an index field, wherein the index message is for receipt by successive enclosures, and wherein each successive enclosure comprises logic for examining the index field to determine whether it should process the message or pass it to the next successive enclosure.

21. The apparatus of claim 1, wherein the logic is configured to:

receive a poll message;

include the enclosure address of the enclosure in a response message generated in response to the poll message;

receive an index message including an index field and a new enclosure address;

examine the index field to ascertain whether the index message should be processed; and

replace the enclosure address with the new enclosure address if the index message should be processed.

22. The apparatus of claim 21 wherein, n response to examining the index field, the logic is configured to send the index message to another enclosure if the index message should not be processed.

23. The apparatus of claim 1, wherein:

each enclosure comprises a midplane having non-volatile memory configured to store the non-unique enclosure address of the enclosure; and

when automatically setting the unique enclosure address, a management interface of each enclosure is configured to receive a management message from an enclosure of the plurality of enclosures, decode the management message to retrieve the unique enclosure address, and write the unique enclosure address of the enclosure to the non-volatile memory of the midplane of the enclosure retrieved from the received management message.

24. The apparatus of claim 23, wherein:

a first enclosure of the plurality of enclosures comprises a system processor and each remaining enclosure of the plurality of enclosures comprises link control cards;

the system processor of the first enclosure is configured to initiate transmission of the management message among the plurality of enclosures; and

the link control cards are configured to form a Fibre Channel Arbitrated Loop among the plurality of devices of the plurality of enclosures when in operation, the plurality of devices being configured as disk drives.

25. The apparatus of claim 24, wherein the system processor of the first enclosure is configured to:

detect a number of enclosures connected on the Fibre Channel Arbitrated Loop; and

if the number of enclosures connected on the Fibre Channel Arbitrated Loop is greater than eight enclosures, transmit a management message to eight of the enclosures to cause the management interface of each of the eight enclosures to write the unique enclosure address of the enclosure to the non-volatile memory of the midplane of the enclosure.

2. Apparatus comprising:

a plurality of enclosures, each enclosure containing a plurality of devices, each device requiring a unique device address related to the enclosure in which it resides, each enclosure initially having a non-unique enclosure address associated with itself for use in addressing devices in the enclosure;

logic for setting a unique enclosure address for each enclosure for use in addressing devices in the enclosure;

wherein each non-unique enclosure address indicates that the corresponding enclosure is not initialized; and

the logic is configured to automatically set the unique enclosure address for each enclosure in response to detecting the non-unique enclosure address upon initialization of the enclosures.

3. The apparatus of claim 2 wherein the enclosures are interconnected by a communications medium, and wherein the logic causes messages to be exchanged between the enclosures via the communications medium to set the enclosure addresses.

4. The apparatus of claim 2 wherein the enclosure address is stored in a non- volatile memory.

5. The apparatus of claim 2 wherein the devices are disk drives.

6. The apparatus of claim 3 wherein the communications medium is a Fibre Channel Arbitrated loop, and wherein the unique device address is an ALPA.

26. The apparatus of claim 2, wherein:

each enclosure comprises a midplane having non-volatile memory configured to store the non-unique enclosure address of the enclosure; and

when automatically setting the unique enclosure address, a management interface of each enclosure is configured to receive a management message from an enclosure of the plurality of enclosures, decode the management message to retrieve the unique enclosure address, and write the unique enclosure address of the enclosure to the non-volatile memory of the midplane of the enclosure retrieved from the received management message.

27. The apparatus of claim 26, wherein:

a first enclosure of the plurality of enclosures comprises a system processor and each remaining enclosure of the plurality of enclosures comprises link control cards;

the system processor of the first enclosure is configured to initiate transmission of the management message among the plurality of enclosures; and

the link control cards are configured to form a Fibre Channel Arbitrated Loop among the plurality of devices of the plurality of enclosures when in operation, the plurality of devices being configured as disk drives.

28. The apparatus of claim 27, wherein the system processor of the first enclosure is configured to:

detect a number of enclosures connected on the Fibre Channel Arbitrated Loop; and

if the number of enclosures connected on the Fibre Channel Arbitrated Loop is greater than eight enclosures, transmit a management message to eight of the enclosures to cause the management interface of each of the eight enclosures to write the unique enclosure address of the enclosure to the non-volatile memory of the midplane of the enclosure.

7. A method comprising the steps of:

providing a plurality of enclosures, each enclosure containing a plurality of devices, each enclosure initially having a non-unique enclosure address associated with itself for use in addressing devices in the enclosure; and

automatically setting via software a unique enclosure address for each enclosure for use in addressing devices in the enclosure;

each non-unique enclosure address indicating that the corresponding enclosure is not initialized; and

automatically setting comprises automatically setting via software the unique enclosure address for each enclosure for use in addressing devices in the enclosure in response to detecting the non-unique enclosure address upon initialization of the enclosures.

8. A method comprising the steps of:

providing a plurality of enclosures, each enclosure containing a plurality of devices, each device requiring a unique device address related to the enclosure in which it resides, each enclosure initially having a non-unique enclosure address associated with itself for use in addressing devices in the enclosure; and

setting a unique enclosure address for each enclosure via software for use in addressing devices in the enclosure;

each non-unique enclosure address indicating that the corresponding enclosure is not initialized; and

setting the unique enclosure address comprises setting the unique enclosure address for each enclosure via software for use in addressing devices in the enclosure in response to detecting the non-unique enclosure address upon initialization of the enclosures.

9. The method of claim 8 wherein the enclosures are interconnected by a communications medium, and wherein the software causes messages to be exchanged between the enclosures via the communications medium to set the enclosure addresses.

10. The method of claim 8 wherein the enclosure address is stored in a non-volatile memory.

11. The method of claim 8 wherein the devices are disk drives.

12. The method of claim 11 wherein the communications medium is a Fibre Channel Arbitrated loop, and wherein the unique device address is an ALPA.

13. A program product comprising a computer readable medium having embodied therein a computer program for storing data, the program product comprising:

logic for detecting a non-unique enclosure address for each enclosure of a plurality of enclosures upon initialization of the enclosures, each non-unique enclosure address indicating that the corresponding enclosure is not initialized;

logic for automatically setting a unique enclosure address for each enclosure of the plurality of enclosures, each enclosure containing a plurality of devices, each enclosure initially having the non-unique enclosure address associated with itself, each enclosure address for use in addressing devices in the respective enclosure.

14. A program product comprising a computer readable medium having embodied therein a computer program for storing data, the program product comprising:

logic for detecting a non-unique enclosure address for each enclosure of a plurality of enclosures upon initialization of the enclosures, each non-unique enclosure address indicating that the corresponding enclosure is not initialized;

logic for setting a unique enclosure address for each enclosure of the plurality of enclosures, each enclosure containing a plurality of devices, each device requiring a unique device address related to the enclosure in which it resides, each enclosure initially having the non-unique enclosure address associated with itself, each enclosure address for use in addressing devices in the respective enclosure.

15. The program product of claim 14 wherein the enclosures are interconnected by a communications medium, and wherein the program product causes messages to be exchanged between the enclosures via the communications medium to set the enclosure addresses.

16. The program product of claim 14 wherein the enclosure address is stored in a non-volatile memory.

17. The program product of claim 14 wherein the devices are disk drives.

18. The program product of claim 17 wherein the communications medium is a Fibre Channel Arbitrated loop, and wherein the unique device address is an ALPA.