Hybrid hard disk drive control method and recording medium and apparatus suitable therefore

1. A method of controlling a hybrid hard disk drive comprising a hard disk and a non-volatile cache, the method comprising:

determining whether a no-write number of blocks in the non-volatile cache exceeds a no-write threshold; and

permanently deactivating a non-volatile cache support mode to prevent further use of the non-volatile cache when it is determined that the no-write number of the non-volatile cache exceeds the no-write threshold.

2. The method of claim 1 , wherein the determining of the no-write number comprises:

determining an erasure number for each block of the non-volatile cache by counting a number of erasing operations performed on each block; and

increasing the no-write number for the non-volatile cache when it is determined that the erasure number of a block of the non-volatile cache exceeds a predetermined erasure limit number.

3. The method of claim 2 , wherein the no-write number is recorded in a spare area of the non-volatile cache or a block assigned to maintenance data.

4. The method of claim 1 , wherein the determining of the no-write number comprises:

determining an erasure number for each block of the non-volatile cache by counting the number of erasing operations performed by the non-volatile cache;

determining a no-write block number by counting the number of blocks for which the erasure number is greater than a predetermined erasure limit number; and

determining whether the no-write number of the non-volatile cache exceeds a predetermined threshold value.

5. The method of claim 4 , wherein the no-write number is recorded in a spare area of the non-volatile cache or a block assigned to maintenance data.

6. The method of claim 4 , wherein the determining of the no-write number further comprises:

detecting a defective block number of the non-volatile cache by detecting the number of defective blocks in the non-volatile cache; and

increasing the no-write number by the defective block number.

7. The method of claim 1 , wherein the determining of the no-write number comprises:

detecting a defective block number of the non-volatile cache by detecting the number of defective blocks in the non-volatile cache; and

determining that the no-write number of the non-volatile cache exceeds a no-write threshold when the defective block number is not less than a predetermined threshold value.

8. The method of claim 1 , wherein the no-write number is recorded in a spare area of the non-volatile cache or a block assigned to maintenance data.

9. The method of claim 1 , further comprising:

notifying a host device of a non-volatile cache support mode being deactivated, wherein the host device is notified when a recording in the non-volatile cache is no longer effective, so that the host device no longer uses the non-volatile cache.

10. A non-transitory computer readable recording medium containing a program executing a method of controlling a hybrid hard disk drive having a hard disk and a non-volatile cache, wherein the method comprises:

determining whether a no-write number of blocks of the non-volatile cache exceeds a no-write threshold; and

permanently deactivating a non-volatile cache support mode to prevent further use of the non-volatile cache when it is determined that the no-write number of the non-volatile cache exceeds the no-write threshold.

11. The non-transitory computer readable recording medium of claim 10 , wherein the determining of the no-write number further comprises:

determining the erasure number for each block of the non-volatile cache by counting the number of erasing operations performed on each block; and

increasing the no-write number when it is determined that the erasure number for a block of the non-volatile cache exceeds a predetermined erasure limit number.

12. The non-transitory computer readable recording medium of claim 10 , wherein the determining of the no-write number further comprises:

determining an erasure number for each block of the non-volatile cache by counting the number of erasing operations performed on each block;

determining a no-write block number by counting the number of blocks for which the erasure number is greater than a predetermined erasure limit number; and

determining that the no-write number of the non-volatile cache exceeds a no-write threshold when the no-write block number is greater than a predetermined threshold value.

13. The non-transitory computer readable recording medium of claim 12 , wherein the determining of the no-write number further comprises:

detecting a defective block number of the non-volatile cache by detecting the number of defective blocks in the non-volatile cache; and

increasing the no-write number by the defective block number.

14. The non-transitory computer readable recording medium of claim 10 , wherein the determining of the usage limit further comprises:

detecting a defective block number of the non-volatile cache by detecting the number of defective blocks in the non-volatile cache; and

determining that the no-write number of the non-volatile cache exceeds a no-write threshold when the defective block number is not less than a predetermined threshold value.

15. The non-transitory computer readable recording medium of claim 10 , wherein the method of controlling a hybrid hard disk drive having a hard disk and a non-volatile cache further comprises:

an operation of notifying a host device of a non-volatile cache support mode being deactivated; and

notifying the host device when recording in the non-volatile cache is no longer effective, so that the host device no longer uses the non-volatile cache.

16. A hybrid hard disk drive comprising:

a hard disk;

a non-volatile cache; and

a control portion to control recording of data from a host on the hard disk and the non- volatile cache,

wherein the control portion determines whether a no-write number of the non-volatile cache exceeds a no-write threshold and permanently deactivates a non-volatile cache support mode to prevent further use of the non-volatile cache when it is determined that the no-write number of the non-volatile cache exceeds the no-write threshold.

17. The hybrid hard disk drive of claim 16 , wherein the control portion notifies the host device when recording in the non-volatile cache is no longer effective, so that the host device no longer uses the non-volatile cache.

18. A method of a hybrid hard disk drive comprising a hard disk and a non-volatile cache, the method comprising:

detecting a defective block number of a non-volatile cache by detecting the number of defective blocks in the non-volatile cache;

determining whether the defective block number equals or exceeds a predetermined threshold value; and

permanently deactivating a non-volatile cache support mode to prevent further use of the non-volatile cache when it is determined that the defective block number equals or exceeds the predetermined threshold value.

19. The method of claim 18 , further comprising:

remapping the defective blocks;

replacing the defective blocks by spare blocks; and

increasing the defective block number.

20. The method of claim 19 , further comprising:

executing a command given by a host when the defective block number is determined to exceed the predetermined limit block number; and

notifying the host of the deactivation.