Remote data mirroring system having a service processor

• US 6,625,705 B2
• Filed: 08/20/2002
• Issued: 09/23/2003
• Est. Priority Date: 04/23/1993
• Status: Expired due to Term

• Current Assignee: EMC Corporation (Dell Technologies Inc.)
• Original Assignee: EMC Corporation (Dell Technologies Inc.)
• Inventors: Vishlitzky, Natan, Alterescu, Bruno, Yanai, Moshe, Shklarsky, Gadi G., Castel, Daniel D. C.
• Primary Examiner(s): Thai, Tuan V.
• Application Number:
  US10/224,211
• Publication Number:
  US 20020194442A1
• Time in Patent Office: 399 Days
• Field of Search: 711/154, 711/156, 711/161, 711/162, 711/165, 714/5, 714/6, 714/7, 714/718
• US Class Current: 711/162
• CPC Class Codes: G06F 11/2066 Optimisation of the communication load
• CPC Class Codes: G06F 11/2071 using a plurality of controllers
• CPC Class Codes: G06F 11/2074 Asynchronous techniques
• CPC Class Codes: G06F 11/2079 Bidirectional techniques
• CPC Class Codes: G06F 11/2082 Data synchronisation
• 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 3/0608 Saving storage space on storage systems
• CPC Class Codes: G06F 3/061 Improving I/O performance
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/064 Management of blocks
• CPC Class Codes: G06F 3/065 Replication mechanisms
• 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: G11B 20/1217 on discs
• CPC Class Codes: H04L 67/1095 Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes
• CPC Class Codes: H04L 69/26 Special purpose or proprietary protocols or architectures network applications for proprietary or special purpose networking environments H04L67/12
• CPC Class Codes: H04L 69/40 for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection management of faults, events, alarms or notifications in data switching networks H04L41/06
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: Y10S 707/99942 Manipulating data structure, e.g. compression, compaction, compilation

Abstract

A primary data storage system is linked to a geographically remote secondary data storage system for automatically maintaining a remote copy of the data in the primary storage. Each of the data storage systems has at least one data storage device, a cache memory, a data storage system controller, and a service processor for servicing the data storage system. The primary and secondary service processors are linked to permit remote system configuration and remote software programming of the secondary data storage system, and to exchange a report of all the non-valid, out of sync tracks. The service processors can also perform the task of scanning for remote write pending bits to invoke the remote copy task, and checking for invalid track bits to invoke a task for copying data from a known good storage device to the device with the invalid track bit set.

Claims

1. A remote data mirroring system for storing data from a host computer into primary data storage, and automatically, without intervention from the host computer, copying the data into secondary storage geographically remote from the primary data storage, said remote data mirroring system comprising:

a primary data storage system including at least one primary data storage device providing the primary data storage, the primary data storage system also including a primary cache memory and at least one primary data storage system controller coupled to the primary cache memory and the primary data storage device for controlling the storing of the data from the host computer into the primary data storage; and

a secondary data storage system geographically removed from the primary data storage system, the secondary data storage system being coupled to the primary data storage system by a communication link for transmission of the data from the primary data storage system to the secondary data storage system, the secondary data storage system including at least one secondary data storage device providing the secondary data storage, the secondary data storage system also including a secondary cache memory and at least one secondary data storage system controller coupled to the secondary cache memory and the secondary data storage device for controlling the storage of the data from the primary data storage system into the secondary data storage;

wherein the primary data storage system is responsive to a command from the host computer to write data by initially storing the data on the primary cache memory, and subsequently transferring the data from the primary cache memory to the primary data storage device and also across the communications link to the secondary data storage system for storage in the secondary data storage device;

wherein the primary data storage system includes a primary service processor coupled to the primary data storage system controller for servicing of the primary data storage system controller, the secondary data storage system includes a secondary service processor coupled to the secondary data storage system controller for servicing of the secondary data storage system controller, and the primary service processor is coupled to the secondary service processor for transfer of service information.

2. The remote data mirroring system of claim 1, which includes a signal path coupling the primary service processor to the secondary service processor for the transfer of the service information, the signal path being independent of the communications link coupling the secondary data storage system to the primary data storage system for transmission of the data from the primary data storage system to the secondary data storage system.

3. The remote data mirroring system of claim 1, wherein the primary service processor provides at least one of repair, service, or status access to the primary data storage system controller.

4. The remote data mirroring system of claim 1, wherein the secondary service processor is coupled to the primary service processor for remote system configuration of the secondary data storage system.

5. The remote data mirroring system of claim 1, wherein the wherein the secondary service processor is coupled to the primary service processor in order for the primary service processor to provide remote software programming of the secondary data storage system.

6. The remote data mirroring system of claim 1, wherein the secondary service processor is coupled to the primary service processor in order for the primary service processor to provide a host base point of control of the secondary data storage system.

7. The remote data mirroring system of claim 1, wherein at least one of the service processors scans an index for write pending indicators and invokes a copy task which copies write-pending data from the primary data storage system to the secondary data storage system.

8. The remote data mirroring system of claim 1, wherein at least one of the service processors checks invalid track indicators on each data storage device, and if an invalid track indicator is found to indicate an invalid track, a copy task is invoked to copy the data from the known good data storage device to the data storage device with the invalid track indicator indicating an invalid track.

9. The remote data mirroring system as claimed in claim 1, wherein at least one of the service processors provides a report of all non-valid, out of sync tracks.

10. The remote data mirroring system as claimed in claim 1, wherein as soon as a non-accessible data storage device becomes accessible, then automatically, as a background operation, the remote data mirroring system re-synchronizes the data storage devices.

11. The remote data mirroring system of claim 1, wherein the service information transferred between the primary service processor and the secondary service processor includes a report of non-valid, out of sync tracks.

12. The remote data mirroring system as claimed in claim 1, wherein the primary service processor stores a log file of pending data which has yet to be written to the secondary data storage device.

13. A remote data mirroring system for storing data from a host computer into primary data storage, and automatically, without intervention from the host computer, copying the data into secondary storage geographically remote from the primary data storage, said remote data mirroring system comprising:

a primary data storage system including at least one primary data storage device providing the primary data storage, the primary data storage system also including a primary cache memory and at least one primary data storage system controller coupled to the primary cache memory and the primary data storage device for controlling the storing of the data from the host computer into the primary data storage; and

a secondary data storage system geographically removed from the primary data storage system, the secondary data storage system being coupled to the primary data storage system by a communication link for transmission of the data from the primary data storage system to the secondary data storage system, the secondary data storage system including at least one secondary data storage device providing the secondary data storage, the secondary data storage system also including a secondary cache memory and at least one secondary data storage system controller coupled to the secondary cache memory and the secondary data storage device for controlling the storage of the data from the primary data storage system into the secondary data storage;

wherein the primary data storage system is responsive to a command from the host computer to write data by initially storing the data on the primary cache memory, and subsequently transferring the data from the primary cache memory to the primary data storage device and also across the communications link to the secondary data storage system for storage in the secondary data storage device;

wherein the primary data storage system includes a primary service processor coupled to the primary data storage system controller for servicing of the primary data storage system controller, the secondary data storage system includes a secondary service processor coupled to the secondary data storage system controller for servicing of the secondary data storage system controller, and at least the primary service processor participates in the production or maintenance of the copy of the data in the secondary data storage.

14. The remote data mirroring system of claim 13, wherein the primary service processor is coupled to the secondary service processor for transfer of service information.

15. The remote data mirroring system of claim 14, which includes a signal path coupling the primary service processor to the secondary service processor for transfer of the service information, the signal path being independent of the communications link coupling the secondary data storage system to the primary data storage system for transmission of the data from the primary data storage system to the secondary data storage system.

16. The remote data mirroring system of claim 13, wherein the primary service processor provides at least one of repair, service, or status access to the primary data storage system controller.

17. The remote data mirroring system of claim 13, wherein the secondary service processor is coupled to the primary service processor for remote system configuration of the secondary data storage system.

18. The remote data mirroring system of claim 13, wherein the secondary service processor is coupled to the primary service processor in order for the primary service processor to provide remote software programming of the secondary data storage system.

19. The remote data mirroring system of claim 13, wherein the secondary service processor is coupled to the primary service processor in order for the primary data storage system to provide a host base point of control of the secondary data storage system.

20. The remote data mirroring system of claim 13, wherein at least one of the service processors scans an index for write pending indicators and invokes a copy task which copies write-pending data from the primary data storage system to the secondary data storage system.

21. The remote data mirroring system of claim 13, wherein at least one of the service processors checks invalid track indicators on each data storage device, and if an invalid track indicator is found to indicate an invalid track, a copy task is invoked to copy the data from the known good data storage device to the data storage device with the invalid track indicator indicating an invalid track.

22. The remote data mirroring system as claimed in claim 13, wherein at least one of the service processors provides a report of all non-valid, out of sync tracks.

23. The remote data mirroring system as claimed in claim 13, wherein as soon as a non-accessible data storage device becomes accessible, then automatically, as a background operation, the remote data mirroring system re-synchronizes the data storage devices.

24. The remote data mirroring system of claim 13, wherein the primary service processor is coupled to the secondary service processor for transfer of a report of non-valid, out of sync tracks.

25. The remote data mirroring system as claimed in claim 13, wherein the primary service processor stores a log file of pending data which has yet to be written to the secondary data storage device.

26. A remote data mirroring system for storing data from a host computer into primary data storage, and automatically, without intervention from the host computer, copying the data into secondary storage geographically remote from the primary data storage, said remote data mirroring system comprising:

a primary data storage system including at least one primary data storage device providing the primary data storage, the primary data storage system also including a primary cache memory and at least one primary data storage system controller coupled to the primary cache memory and the primary data storage device for controlling the storing of the data from the host computer into the primary data storage; and

a secondary data storage system geographically removed from the primary data storage system, the secondary data storage system being coupled to the primary data storage system by a communication link for transmission of the data from the primary data storage system to the secondary data storage system, the secondary data storage system including at least one secondary data storage device providing the secondary data storage, the secondary data storage system also including a secondary cache memory and at least one secondary data storage system controller coupled to the secondary cache memory and the secondary data storage device for controlling the storage of the data from the primary data storage system into the secondary data storage;

wherein the primary data storage system is responsive to a command from the host computer to write data by initially storing the data on the primary cache memory, and subsequently transferring the data from the primary cache memory to the primary data storage device and also across the communications link to the secondary data storage system for storage in the secondary data storage device;

wherein the primary data storage system includes a primary service processor coupled to the primary data storage system controller for servicing of the primary data storage system controller, the secondary data storage system includes a secondary service processor coupled to the secondary data storage system controller for servicing of the secondary data storage system controller, and the primary service processor is coupled to the secondary service processor for at least one of remote system configuration, remote software programming, or a host base point of control for the secondary data storage system.

27. The remote data mirroring system of claim 26, which includes a signal path coupling the primary service processor to the secondary service processor for transfer of service information, the signal path being independent of the communications link coupling the secondary data storage system to the primary data storage system for transmission of the data from the primary data storage system to the secondary data storage system.

28. The remote data mirroring system of claim 26, wherein the primary service processor provides at least one of repair, service, or status access to the primary data storage system controller.

29. The remote data mirroring system of claim 26, wherein at least the primary service processor participates in the production or maintenance of the copy of the data in the secondary data storage.

30. The remote data mirroring system as claimed in claim 26, wherein at least one of the service processors provides a report of all non-valid, out of sync tracks.

31. A remote data mirroring system for storing data from a host computer into primary data storage, and automatically, without intervention from the host computer, copying the data into secondary storage geographically remote from the primary storage, said remote data mirroring system comprising:

a primary data storage system including at least one primary data storage device providing the primary data storage, the primary data storage system also including a primary cache memory and at least one primary data storage system controller coupled to the primary cache memory and the primary data storage device for controlling the storing of the data from the host computer into the primary data storage; and

a secondary data storage system geographically removed from the primary data storage system, the secondary data storage system being coupled to the primary data storage system by a communication link for transmission of the data from the primary data storage system to the secondary data storage system, the secondary data storage system including at least one secondary data storage device providing the secondary data storage, the secondary data storage system also including a secondary cache memory and at least one secondary data storage system controller coupled to the secondary cache memory and the secondary data storage device for controlling the storage of the data from the primary data storage system into the secondary data storage;

wherein the primary data storage system controller is responsive to a command from the host computer to write data by initially storing the data on the primary cache memory and providing an indicator that the data is write pending to each of the primary data storage and the secondary data storage, and in a background task, transferring write-pending data from the primary cache memory to the primary data storage device; and

wherein the secondary data storage system controller is responsive to receipt of the data transmitted over the communications link from the primary data storage system by initially storing the data on the secondary cache memory and providing an indicator that the data is write pending to the secondary data storage, and in a background task, transferring the write-pending data from the secondary cache memory to the secondary data storage device; and

wherein the primary data storage system includes a primary service processor coupled to the primary data storage system controller for providing repair, service, and status access to the primary data storage system controller, and the secondary data storage system includes a secondary service processor coupled to the secondary data storage system controller for servicing of the secondary data storage system controller, and the secondary service processor is linked to the primary service processor by a signal path for remote system configuration, remote software programming, and a host base point of control for the secondary data storage system.

32. The remote data mirroring system of claim 31, which includes a signal path coupling the primary service processor to the secondary service processor for transfer of service information, the signal path being independent of the communications link coupling the secondary data storage system to the primary data storage system for transmission of the data from the primary data storage system to the secondary data storage system.

33. The remote data mirroring system of claim 31, wherein at least one of the service processors periodically scans for write pending indicators indicating that a copy is pending from the primary data storage system to the secondary data storage system and invokes a copy task which copies write-pending data from the primary data storage system to the secondary data storage system.

34. The remote data mirroring system of claim 31, wherein at least one of the service processors checks for invalid track indicators on each data storage device, and if an invalid track indicator is found to indicate an invalid track, a copy task is invoked to copy the data from the known good data storage device to the data storage device with the invalid track indicator indicating an invalid track.

35. The remote data mirroring system as claimed in claim 31, wherein at least one of the service processors provides a report of all non-valid, out of sync tracks.