Alignment-unit-based virtual formatting methods and devices employing the methods

In various embodiments, the present invention provides virtual disk formatting by intermediate devices including: (1) a storage shelf router and the storage shelf in which the storage-shelf is included, to external computing entities, such as disk-array controllers and host computers; (2) an I/O controller; and (3) a storage-bridge device. Additional embodiments of the present invention enhance virtual formatting by using additional padding, in a dual-abstraction method, to efficiently align virtual-block reads with underlying device blocks. Yet additional embodiments of the present invention allow for tracking and correcting device blocks corrupted during READ-MODIFY operations that occur during virtual-block WRITE operations. Various intermediate devices may employ two or more of the virtual formatting, dual abstraction, and corrupted-device-block tracking methods.