Checking for proper locations of storage device in a storage device array

• US 5,598,528 A
• Filed: 10/19/1994
• Issued: 01/28/1997
• Est. Priority Date: 11/15/1991
• Status: Expired due to Term

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Larson, David, Stubbs, Robert E., Edstrom, Gene
• Primary Examiner(s): Chan, Eddie P.
• Assistant Examiner(s): BRAGDON, REGINALD GLENWOOD
• Application Number:
  US08/325,989
• Time in Patent Office: 832 Days
• Field of Search: 395/575, 395/425, 395/182.05, 395/183.18, 395/441, 371/10.1
• US Class Current: 714/6.32
• CPC Class Codes: G06F 11/006 Identification G06F11/2289 takes precedence
• CPC Class Codes: G06F 11/1415 at system level
• CPC Class Codes: G06F 11/2289 by configuration test
• 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 3/0634 by changing the state or mode of one or more devices
• CPC Class Codes: G06F 3/0653 Monitoring storage devices or systems
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD
• CPC Class Codes: G11B 19/00 Driving, starting, stopping record carriers not specifically of filamentary or web form, or of supports therefor; Control thereof; Control of operating function ; Driving both disc and head
• CPC Class Codes: G11B 19/12 by sensing distinguishing features of or on records, e.g. diameter end mark
• CPC Class Codes: G11B 20/1816 Testing
• CPC Class Codes: G11C 29/88 with partially good memories

Abstract

A determination is made as to whether or not storage devices of a storage array are positioned in their proper physical locations in the array. To make the determination, a device identifier for each of the storage devices is utilized, together with a generated logical identifier. In a preferred embodiment, the device identifier is the serial number for the storage device and the logical identifier includes a combination of all the device identifiers for a particular logical volume of the storage array. Preferably, the logical identifier also includes system status information for use in enhancing fault tolerance. The logical identifier is written or updated upon the occurrence of predetermined events or conditions. Using the device identifiers and the logical identifier, an indication can be provided whenever the proper storage devices are not found in the logical volume whereby corrective action can be taken to avoid improper distribution to or reassembly of data from the logical volume.

Claims

1. A method for determining whether each of a plurality of storage devices of a logical volume of storage devices is positioned at a proper physical location, comprising:

providing identifier means on each storage device of a logical volume of storage devices, said providing step including providing a device identifier on each of said storage devices, said device identifier being different for each of said storage devices of said logical volume, said providing step also including writing a logical identifier on each of said storage devices of said logical volume, said logical identifier including all of said device identifiers for said storage devices of said logical volume wherein, for each of said storage devices of said logical volume, said device identifier is provided as part of said logical identifier and is also provided different from said logical identifier and each of said device identifiers is written as part of said logical identifier in a predetermined sequence relative to each of the other of said device identifiers;

reading said identifier means using computer means that includes processor means and controller means for each of said storage devices; and

determining using said computer means whether each of said storage devices of said logical volume is properly located in said logical volume using said identifier means, said determining step including utilizing said logical identifier in combination with one of said device identifiers to determine whether one of said storage devices properly belongs in said logical volume and whether said one storage device is properly located physically within said logical volume, said utilizing step including ascertaining, using said computer means, that said one of said device identifiers among all of said device identifiers of said logical identifier is to be selected as part of said determining step while relying on said predetermined sequence of device identifiers in said logical identifier in executing said determining step.

2. A method, as claimed in claim 1, wherein:

said step of providing said identifier means includes generating said logical identifier whenever at least one of the following occurs;

attaching of one of said storage devices, replacing one of said storage devices, updating defect information for one of said storage devices, reconstructing data for one of said storage devices and changing configuration associated with said logical volume.

3. A method, as claimed in claim 1, wherein:

said step of reading said identifier means includes reading using said controller means a serial number written on each of said storage devices, each of said serial numbers being used as a device identifier.

4. A method, as claimed in claim 1, wherein:

said step of reading occurs after there has been a restoration of power to one or more of said storage devices of said logical volume.

5. A method, as claimed in claim 1, wherein:

said step of determining includes comparing a first of said logical identifiers with a second of said logical identifiers to determine whether they are the same.

6. A method, as claimed in claim 1, wherein:

said step of determining includes comparing each of said device identifiers for each of said storage devices with said logical identifier.

7. An apparatus for determining whether each of a plurality of storage devices of a logical volume of storage devices is found at a proper physical location, comprising:

first means for storing information including distributed data, said first means including a plurality of storage devices together defining a logical volume with each of said storage devices storing said distributed data, each of said storage devices having a device identifier that is different from each device identifier of each of the other of said storage devices of said logical volume, said information further including logical identifier means stored with each of said storage devices of said logical volume, said logical identifier means including all of said device identifiers for each of said storage devices of said logical volume, wherein each of said storage devices has said device identifier as part of said logical identifier means and also has stored thereon its device identifier different from said logical identifier means and in which said logical identifier means for each of said storage devices of said logical volume is the same and each of said device identifiers of said logical identifier means is provided on each of said storage devices in a predetermined sequence relative to each of the other of said device identifiers;

second means for controlling transfer of said distributed data to said storage devices of said logical volume and for reassembling said distributed data received from said storage devices of said logical volume; and

third means operatively associated with said second means for determining whether each of said storage devices having said distributed data properly belongs in said logical volume and for determining whether each of said storage devices is at a proper physical location in said logical volume, wherein said third means, for each of said storage devices of said logical volume, ascertains which one of said device identifiers of said logical identifier means is to be selected during said determining and said third means relies on said predetermined sequence of said device identifiers in said logical identifier means during said determining.

8. An apparatus, as claimed in claim 7, wherein:

said first means includes a number of disk drives with each of said disk drives storage blocks of information received from said second means.

9. An apparatus, as claimed in claim 7, wherein:

said status information includes status related to each of the following;

replacing one of said storage devices of said logical volume, updating defect information for at least one of said storage devices, reconstructing data for at least one of said storage devices and changing configuration by storing distributed data on a replacement storage device for one of said storage devices of said logical volume that has failed.

10. An apparatus, as claimed in claim 7 wherein:

each of said device identifiers includes a serial number written on one of said storage devices.

11. An apparatus, as claimed in claim 7, wherein:

said third means includes means for comparing at least one of said logical identifiers with a logical identifier of another of said storage devices.

12. An apparatus, as claimed in claim 7, wherein:

said third means includes means for comparing one of said device identifiers of said logical identifier with a device identifier for one of said storage devices.

13. A method for determining whether each of a plurality of storage devices of a logical volume of storage devices is positioned at a proper physical location, comprising:

monitoring, using computer means that includes controller means and processing means, occurrences of predetermined events including;

(a) initialization of said storage devices by updating defect maps and allocation of data storage, (b) reconstruction of data for one of said storage devices, (c) a configuration change by storing data on a replacement storage device for one of said storage devices that has failed;

ascertaining that data is to be reconstructed as part of a first data reconstruction;

writing, after said ascertaining step but before said first data reconstruction is completed, identifier means using said controller means to each storage device of said logical volume of said storage devices, said identifier means including status information comprising status related to each of said predetermined events including first status related to said first data reconstruction, said first status being identified by a first bit configuration indicative of the occurrence of said first data reconstruction, said identifier means being written to one of said storage devices of said logical volume being the same as said identifier means that is written to each of the other of said storage devices of said logical volume;

beginning execution of said first data reconstruction using said computer means;

powering on all of said storage devices of said logical volume after disruption of power thereto in which power was disrupted before said first data reconstruction was completed but after said first data reconstruction was begun;

reading said identifier means using said controller means for each of said storage devices after said powering on step;

determining, after said reading step, using said processing means that each of said storage devices of said logical volume is properly located in said logical volume using said identifier means;

completing execution of said first data reconstruction using said computer means after said determining step; and

rewriting said identifier means using said computer means to each said storage device of said logical volume, said identifier means including a second status related to said first data reconstruction after said completing step, said second status being different from said first status and being identified by a second bit configuration indicative of the completion of said first data reconstruction, said identifier means being rewritten to one of said storage devices of said logical volume being the same as said identifier means that is rewritten to each of the other of said storage devices of said logical volume.

14. A method, as claimed in claim 13, wherein:

said identifier means includes a logical identifier that comprises a device identifier for each of said storage devices of said logical volume.

15. A method, as claimed in claim 14, wherein:

said determining step includes comparing at least one logical identifier of one of said storage devices with another logical identifier of another of said storage devices.

16. A method, as claimed in claim 15, wherein:

said determining step further includes comparing at least one of said device identifiers of said logical identifier with a device identifier provided on one of said storage devices.

17. A method for determining whether each of a plurality of storage devices of a logical volume of storage devices is a proper member of the logical volume of storage devices, comprising:

providing a device identifier on each storage device of a logical volume of storage devices, each of the device identifiers on each of said storage devices being different for each of said storage devices of said logical volume;

providing a logical identifier on each of said storage devices of said logical volume, said logical identifier being formed all of said device identifiers for said storage devices of said logical volume;

reading out said logical identifier from each of said storage devices of said logical volume; and

determining whether each of said storage devices of said logical volume is a proper storage device in said logical volume by checking said logical identifier read out in said reading step.

18. A method, as claimed in claim 17, wherein said step of providing the device identifier comprises:

providing an inherent serial number of the storage device as the device identifier.

19. A method, as claimed in claim 17, wherein said step of providing the logical identifier comprises:

associating said logical identifier with said device identifiers in a predetermined sequence.

20. A method, as claimed in claim 19, wherein said step of providing the device identifier comprises:

providing an inherent serial number of the storage device as the device identifier.

21. A method, as claimed in claim 19, wherein said determining step comprises:

comparing a first logical identifier with each of said logical identifiers of said storage devices of the logical volume.

22. A method, as claimed in claim 21, wherein said step of providing the device identifier comprises:

providing an inherent serial number of the storage device as the device identifier.

23. A disk array apparatus having a plurality of storage device of a logical volume, comprising:

means for providing a logical identifier on each of said storage devices of said logical volume, said logical identifier being formed of all of a number of device identifiers, each of which is assigned to each of said storage device of said logical volume, each of the device identifiers is different from each other;

means for reading out said logical identifier from each of said storage devices of said logical volume; and

means for determining whether each of said storage device of said logical volume is a proper storage device in said logical volume by checking said logical identifier read out by said reading means.

24. A disk array apparatus, as claimed in claim 23, wherein:

each of said device identifiers is an inherent serial number of one of the storage device of the logical volume.

25. A dark array apparatus, as claimed in claim 23, wherein:

said logical identifier is associated with said device identifiers in a predetermined sequence.

26. A disk array apparatus, as claimed in claim 25, wherein:

each of said device identifiers is an inherent serial number of one of the storage devices of the logical volume.

27. A disk array apparatus, as claimed in claim 23, wherein said determining means comprises:

means for comparing a first logical identifier with at least one of said logical identifiers of said storage devices of the logical volume.

28. A disk array apparatus, as claimed in claim 27, wherein:

each of said device identifiers is an inherent serial number of one of the storage devices of the logical volume.

29. A disk array apparatus, comprising:

a plurality of storage devices of a logical volume, each of said storage devices having a device identifier, each of the device identifiers on each of said storage devices being different for each of said storage devices of said logical volume and inherent to the respective storage device;

means for dividing information into a plurality of data and storing of the plurality of data on to the respective storage device;

means for providing a logical identifier on each of said storage devices of said logical volume, said logical identifier being formed of all of a number of device identifiers, each of which is assigned to each of said storage devices said logical volume, each of the device identifiers is different from each other;

means for reading out said logical identifier from each of said storage devices of said logical volume; and

means for determining whether each of said storage devices of said logical volume is a proper storage device in said logical volume by checking said logical identifier read out by said reading means.

30. A disk array apparatus, as claimed in claim 29, wherein:

each said device identifiers is an inherent serial number of one of the storage devices of the logical volume.

31. A disk array apparatus, as claimed in claim 29, wherein:

said logical identifier is associated with said device identifiers in a predetermined sequence.

32. A disk array apparatus, as claimed in claim 31, wherein:

each of said device identifiers is an inherent serial number of one of the storage devices of the logical volume.

33. A disk array apparatus, as claimed in claim 29, wherein said determining means comprises:

means for comparing a first logical identifier with each of said logical identifiers of said storage devices of the logical volume.

34. A disk array apparatus, as claimed in claim 33, wherein:

each of said device identifiers is an inherent serial number of one of the storage devices of the logical volume.

35. A disk array apparatus, as claimed in claim 29, further comprising:

means for executing a reconstruction of the information that is the stored data in said plurality of storage devices in accordance with which said determining means has determined that at least one of said storage devices of said logical volume is not a proper storage device in said logical volume.

36. A disk array apparatus, as claimed in claim 35, further comprising:

means for making a logical identifier based on the reconstruction of the information.