Patent ID: 8850124

Claim:
A computer-implemented method for reading data into a disk cache ahead of a read operation, comprising: maintaining a bitmap comprising a plurality of bits, each bit corresponding to a sector of the disk cache and containing data indicating whether the corresponding sector is valid in the disk cache and can be used to satisfy read requests; receiving a request to read a sector of the disk cache; in response to the request, identifying a bit in the bitmap that corresponds to the requested sector of the disk cache; determining whether the disk cache contains valid data for a sector of the disk cache previous to the requested sector by examining a bit in the bitmap previous to the bit that corresponds to the requested sector; and in response to determining that the disk cache contains valid data for the sector of the disk cache previous to the requested sector, reading sequentially into the disk cache one or more sectors of the disk cache corresponding to one or more bits in the bitmap following the bit corresponding to the requested sector until an end of the bitmap is reached.