Non-volatile hard disk drive cache system and method

摘要

A non-volatile hard disk drive cache system is coupled between a processor and a hard disk drive. The cache system includes a control circuit, a non-volatile memory and a volatile memory. The control circuit causes a subset of the data stored in the hard disk drive to be written to the non-volatile memory. In response to a request to read data from the hard disk drive, the control circuit first determines if the requested read data are stored in the non-volatile memory. If so, the requested read data are provided from the non-volatile memory. Otherwise, the requested read data are provided from the hard disk drive. The volatile memory is used as a write buffer and to store disk access statistics, such as the disk drive locations that are most frequently read, which are used by the control circuit to determine which data to store in the non-volatile memory.

主权项

1. A method of storing data in a system having a non-volatile memory and a hard drive, the method comprising:
receiving a plurality of write requests each of which contains write data that are to be stored in a hard drive; storing the write data in the hard drive; and selectively writing in a non-volatile memory a subset of the write data that is to be stored in the hard drive, wherein the subset of the write data corresponds to less than the plurality of the write requests.