Abstract: A mirrored data storage system with a plurality of data storage physical entities (drives) arranged in mirrored pairs in accordance with reliability weightings that have been assigned to each of the drives. Each mirrored pair comprises one drive with at least a median and greater reliability weighting, and one drive with at least a median and lesser reliability weighting. In an example, the assigned reliability weightings are sorted into descending order; with the drives having weightings in the upper half of the sorted order assigned to a first set with greater reliability weighting, and the drives having weightings in the lower half of the sorted order assigned to a second set with lesser reliability weighting. Each mirrored pair has one drive selected from the first set and one drive selected from the second set.

Abstract: A method implemented in a computer infrastructure including a combination of hardware and software includes receiving from a local computing device a request to securely delete a file. The method also includes determining the file is deduplicated. The method further includes determining one of: the file is referred to by at least one other file, and the file is not referred to by another file. The method additionally includes securely deleting links associating the file with the local computing device without deleting the file when the file is referred to by at least one other file. The method also includes securely deleting the file when the file is not referred to by another file.