Method of converting a hybrid hard disk drive to a normal HDD

1. A method of converting a hard disk drive (HDD) from a hybrid HDD to a normal HDD, the HDD having a normal hard disk and a non-volatile cache, the method comprising:

determining whether a mode conversion flag is enabled during a power-on period;

operating the HDD as the normal HDD when the mode conversion flag is enabled;

determining whether an operating mode of the HDD is a normal mode or a hybrid mode when the mode conversion flag is disabled;

operating the HDD as the normal HDD when the operating mode of the HDD is the normal mode;

determining whether the total number of defective blocks in the non-volatile cache is greater than a predetermined threshold when the operating mode of the HDD is the hybrid mode;

operating the HDD as the hybrid HDD when the total number of the defective blocks is not greater than the threshold; and

enabling the mode conversion flag and operating the HDD as the hybrid HDD when the total number of the defective blocks is greater than the threshold.

2. The method of claim 1 wherein the non-volatile cache comprises spare blocks which replace the defective blocks and the threshold is determined according to the total number of the spare blocks.

3. The method of claim 2 wherein the threshold is set to be the total number of the spare blocks.

4. The method of claim 2 wherein the threshold is set to a value obtained by subtracting a user specified margin from the total number of spare blocks.

5. The method of claim 1 wherein the step of determining whether the mode conversion flag is enabled is performed when the system having the HDD is powered on.

6. The method of claim 1 wherein operating the HDD as the normal HDD when the mode conversion flag is enabled further comprises:

moving data stored in the non-volatile cache to the normal hard disk when the mode conversion flag is enabled;

turning the hybrid mode off;

disabling the mode conversion flag; and

operating the HDD as the normal HDD.

7. The method of claim 6 wherein the mode conversion flag is enabled when the total number of defective blocks is greater than the threshold and is disabled when the operating mode of the HDD is converted from the hybrid mode to the normal mode.

8. The method of claim 1 wherein after operating the HDD as the normal HDD or operating the HDD as the hybrid HDD, the method further comprising powering off the system having the HDD.

9. The method of claim 8 wherein if the total number of the defective blocks is not greater than the threshold, the method further comprising;

after operating the HDD as the hybrid HDD and before powering off the system having the HDD, determining again whether the total number of defective blocks in the non-volatile cache is greater than the threshold.

10. A method of converting a hard disk drive (HDD) from a hybrid HDD to a normal HDD, the HDD having a normal hard disk and a non-volatile cache, the method comprising:

during an Nth power-on of a system having the HDD, if a mode conversion flag is disabled, if an operating mode of the HDD is a hybrid mode, and if the total number of defective blocks in the non-volatile cache is not greater than a predetermined threshold, then operating the HDD as the hybrid HDD and powering off the system;

during an N+1th power-on of the system, if the mode conversion flag is disabled, if an operating mode of the HDD is the hybrid mode, and if the total number of defective blocks in the non-volatile cache is greater than the threshold, then enabling the mode conversion flag, operating the HDD as the hybrid HDD and powering off the system; and

during an N+2th power-on of the system, if the mode conversion flag is enabled then turning the hybrid mode off and operating the HDD as the normal HDD.

11. The method of claim 10 wherein the turning off of the hybrid mode and operating the HDD as the normal HDD, further comprises:

moving data stored in the non-volatile cache to the normal hard disk;

turning the hybrid mode off;

disabling the mode conversion flag; and

operating the HDD as the normal HDD.

12. The method of claim 11 further comprising:

after the operating of the HDD as the normal HDD, powering off the system having the HDD; and

during an N+3th power-on of the system, if the mode conversion flag is disabled and the operating mode of the HDD is the normal mode, then operating the HDD as the normal HDD.

13. A method of converting a hard disk drive (HDD) from a hybrid HDD to a normal HDD, the HDD having a normal hard disk and a non-volatile cache, the method comprising:

during an Nth power-on of a system having the HDD, if a mode conversion flag is disabled, if an operating mode of the HDD is a hybrid mode and if the total number of defective blocks in the non-volatile cache is not greater than the threshold, then operating the HDD as the hybrid HDD;

determining again whether the total number of the defective blocks is greater than the threshold, and if the total number of the defective blocks is greater than the threshold, enabling the mode conversion flag, operating the HDD as the hybrid HDD, and powering off the system; and

during an N+1th power-on of the system, if the mode conversion flag is enabled, turning the hybrid mode off and operating the HDD as the normal HDD.

14. The method of claim 13 wherein the turning off of the hybrid mode and the operating of the HDD as the normal HDD, further comprises:

moving data stored in the non-volatile cache to the normal hard disk;

turning the hybrid mode off;

disabling the mode conversion flag; and

operating the HDD as the normal HDD.

15. The method of claim 14 further comprising:

after operating the HDD as the normal HDD, powering off the system; and

during an N+2th power-on of the system, if the mode conversion flag is disabled and the operating mode of the HDD is the normal mode, then operating the HDD as the normal HDD.

16. A method of converting a hard disk drive (HDD) from a hybrid HDD to a normal HDD, the HDD having a normal hard disk and a non-volatile cache, the method comprising:

determining whether a mode conversion flag is enabled during a power-on period;

if the mode conversion flag is enabled, operating the HDD as the normal HDD;

if the mode conversion flag is disabled, determining whether the total number of defective blocks in the non-volatile cache is greater than a predetermined threshold;

if the total number of the defective blocks is not greater than the threshold, operating the HDD as the hybrid HDD; and

if the total number of the defective blocks is greater than the threshold, enabling the mode conversion flag and operating the HDD as the hybrid HDD.

17. The method of claim 16 wherein the non-volatile cache comprises spare blocks replacing the defective blocks, and the threshold is set to the total number of the spare blocks or a value obtained by subtracting a user specified margin from the total number of the spare blocks.

18. The method of claim 16 wherein the step of determining whether the mode conversion flag is enabled, is performed when a system having the HDD is powered on.

19. The method of claim 16 wherein operating the HDD as the normal HDD further comprises:

if the mode conversion flag is enabled, determining whether the hybrid mode is turned off;

if the hybrid mode is not turned off, moving data stored in the non-volatile cache to the normal hard disk, turning the hybrid mode off, and operating the HDD as the normal HDD; and

if the hybrid mode is turned off, operating the HDD as the normal HDD.

20. The method of claim 19 wherein the mode conversion flag is enabled when the total number of the defective blocks is greater than the threshold, and maintains the enabled state even when an operating mode of the HDD is converted from the hybrid mode to a normal mode.

21. The method of claim 16 further comprising:

after the operating of the HDD as the normal HDD or the operating of the HDD as the hybrid HDD, powering off the system having the HDD.

22. The method of claim 21 wherein if the total number of the defective blocks is not greater than the threshold the method further comprises:

after operating the HDD as the hybrid HDD and before powering off the system having the HDD, determining again whether the total number of defective blocks is greater than the threshold.

23. A method of converting a hard disk drive (HDD) from a hybrid HDD to a normal HDD, the HDD having a normal hard disk and a non-volatile cache, the method comprising:

during an Nth power-on of a system having the HDD, if a mode conversion flag is disabled and the total number of defective blocks in the non-volatile cache is not greater than a predetermined threshold, then operating the HDD as the hybrid HDD and powering off the system;

during an N+1th power-on of the system, if the mode conversion flag is disabled and the total number of the defective blocks is greater than the threshold, then enabling the mode conversion flag, operating the HDD as the hybrid HDD, and powering off the system; and

during an N+2th power-on of the system, if the mode conversion flag is enabled and a hybrid operating mode is not turned off, then turning the hybrid mode off and operating the HDD as the normal HDD.

24. The method of claim 23 wherein, during an N+3th power-on of the system, if the mode conversion flag is enabled and the hybrid mode is turned off, then operating the HDD as the normal HDD.