When data changes in LBAs of a disk storage, the IDs of changed LBAs are written to a cache, with the LBAs being hashed to render a hash result. The hash result and contents of the cache are written to a file on the disk, the cache flushed, and the hash result written back to the cache for hashing together with subsequent changed LBAs. The process repeats. In this way, the hash result in the most current file on the disk can be compared with the hash result in cache, and if the two match, it indicates that the files on the disk contain an accurate record of changed LBAs.