1. In a computing environment, a method performed at least in part on at least one processor or hardware, or both, comprising, partitioning a file into chunks that satisfy at least one chunk size restriction, including, establishing a minimum chunk size and a maximum chunk size for performing a chunk boundary determination, and for at least each file position that is within the chunk size restriction, determining an actual chunk boundary by comparing a signature that is representative of a rolling window corresponding to that position to an initial target pattern, and if the initial target pattern is matched, identifying a chunk boundary candidate or the actual chunk boundary based upon one or more other signature and target pattern comparisons, and if the actual chunk boundary is not set, the maximum chunk size is reached and at least one candidate chunk boundary exists at a position that satisfies the chunk size restriction, setting the actual chunk boundary by selecting a selected chunk boundary candidate and setting the selected chunk boundary candidate as the actual chunk boundary based upon a signature ranking associated with each candidate.