Physical medium information in file system header

• US 6,249,838 B1
• Filed: 12/28/1998
• Issued: 06/19/2001
• Est. Priority Date: 12/28/1998
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Kon, Ronnie B.
• Primary Examiner(s): Nguyen, Than
• Application Number:
  US09/221,035
• Time in Patent Office: 904 Days
• Field of Search: 711/4, 711/101, 711/102-106, 365/185.33, 365/230.03, 320/112
• US Class Current: 711/103
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G11C 16/349 Arrangements for evaluating degradation, retention or wearout, e.g. by counting erase cycles
• CPC Class Codes: G11C 16/3495 Circuits or methods to detect or delay wearout of nonvolatile EPROM or EEPROM memory devices, e.g. by counting numbers of erase or reprogram cycles, by using multiple memory areas serially or cyclically

Abstract

Data storage units, such as flash memory, nonvolatile random access memory and like, are provided with information stored therein, or physically coupled thereto, which indicates, or can be used to determine, remaining or impending end of lifetime of the data storage unit or its components. In a flash memory embodiment, a counter initialized to the number of maximum permissible flash memory erasures is stored in a counter, such as in the header portion of the flash memory. The counter is decremented with each erasure and, as the counter approaches zero, appropriate actions can be taken such as warning the user, support personnel, vendor and the like and/or disabling the flash memory.

Claims

1. Apparatus for a data storage unit having at least a main data storage medium for storing data, comprising:

an electronic data storage device, comprising a header portion of said main data storage medium, which stores at least first remaining-expected-lifetime (REL) information usable for determining remaining expected lifetime of said data storage unit, said electronic data storage device being physically coupled to said data storage unit;

at least a first output line for outputting at least a first signal related to the remaining-expected-lifetime of said data storage unit.

2. Apparatus, as claimed in claim 1, wherein said data storage unit is selected from the group consisting of:

flash memory;

non-volatile RAM;

a tape drive;

a re-writable disk;

a hard disk drive; and

a removable media hard disk drive.

3. Apparatus, as claimed in claim 1 wherein said electronic data storage device is separate from said main data storage medium.

4. Apparatus, as claimed in claim 1 wherein said REL information is updated in response to usage of said data storage unit.

5. Apparatus, as claimed in claim 4, further comprising logic circuitry, physically coupled to said data storage unit, which updates said REL information.

6. A method for use with a data storage unit having at least a main data storage medium for storing data, comprising:

providing an electronic data storage device different from said main data storage medium, said electronic data storage device being physically coupled to said data storage unit;

storing system information in said electronic data storage device;

outputting said system information from said data storage device;

wherein said system information includes at least first remaining-expected-lifetime (REL) information usable for determining remaining expected lifetime of said data storage unit and wherein said step of outputting includes outputting, from said data storage unit, at least a first signal related to the remaining-expected-lifetime of said data storage unit;

displaying a warning of impending end of lifetime of said data storage unit, in response to said outputting of said first signal.

7. A method, as claimed in claim 6 further comprising updating said REL information in response to usage of said data storage unit.

8. A method, as claimed in claim 6, further comprising sending, to a remote computer, a message indicating impending end of lifetime of said data storage unit, in response to said outputting of said first signal.

9. A method, as claimed in claim 6, further comprising disabling said data storage unit in response to said outputting of said first signal.

10. A method, as claimed in claim 6, wherein said data storage unit is a hard disk drive, and further comprising storing superblock information relating to said hard disk drive on said electronic data storage device.

11. Apparatus for a data storage unit having at least a main data storage medium for storing data, comprising:

electronic means, comprising a header portion of said main data storage medium for storing at least first remaining-expected-lifetime (REL) information usable for determining remaining expected lifetime of said data storage unit, said electronic means for storing being physically coupled to said data storage unit;

means for outputting at least a first signal related to the remaining-expected-lifetime of said data storage unit.

12. Apparatus, as claimed in claim 11, wherein said electronic means for storing comprises a portion of said main data storage medium.

13. Apparatus, as claimed in claim 11 wherein said electronic means for storing is separate from said main data storage medium.

14. Apparatus, as claimed in claim 11 further comprising means for updating said REL information in response to usage of said data storage unit.

15. Apparatus, as claimed in claim 14, wherein said means for updating is physically coupled to said data storage unit.

16. Apparatus as claimed in claim 11, wherein said data storage unit comprises a flash memory, said header region including at least a first counter initialized to a first value, further comprising:

read/write circuitry configured to read and write from and to said main memory; and

logic circuitry configured to monitor erase operations performed on said flash memory and, in response, decrement said counter.

17. Apparatus as claimed in claim 16, wherein said logic circuitry is further configured to output, from said flash memory, at least a first signal when said counter stores a value which is less than at least a first threshold value.

18. A non-volatile RAM comprising:

a main memory for storing data, said main memory including a header region, said header region including at least a first counter initialized to a first value;

a battery for providing power for refresh operations when external power is unavailable;

read/write circuitry configured to read and write from and to said main memory;

logic circuitry configured to monitor charges of said battery and, in response, incrementing said counter.

19. A non-volatile RAM, as claimed in claim 18, wherein said logic circuitry is further configured to output, from said non-volatile RAM, at least a first signal when said counter stores a value which is greater than at least a first threshold value.