Checksum technique for verifying integrity of disk space reserved for suspend-to-disk operations

摘要

Method and apparatus for implementing a checksum technique for verifying the integrity of hard disk space reserved for use in implementing S2D capabilities is disclosed. In a preferred embodiment, a root block stored in a dedicated, fixed-size S2D partition comprises a plurality of entries each of which contains a pointer to the location of a corresponding pointer block located and a checksum for use in verifying the integrity of the pointer block. Similarly, each pointer block comprises a plurality of entries each of which contains a pointer to the location of a corresponding data block and a checksum for use in verifying the integrity of the data block. When an S2D operation is initiated, an S2D utility of the present invention locates a next available data block in the S2D partition or an extended partition, using the entries in the root block and pointer blocks, computes the checksum for the located data block, compares the computed checksum to the stored checksum for the block and, if the two checksums match writes a portion of RAM to the located block. If at any point, two checksums do not match, an error results and the S2D operation terminates. In one aspect of the invention, an MKS2D utility locates the available blocks of disk space for generating the extended partition, computes a checksum for each block and appropriately fills in the root and pointer blocks with pointers and checksums for use by the S2D utility. In another aspect of the invention, an RMS2D utility deletes the extended partition and returns the data blocks previously allocated thereto to the native OS and/or other partition(s).