Virtual machine data backup

Abstract

Disclosed is a method and system for efficiently backing up a virtual machine file. A virtual machine file is logically divided into a plurality of fixed-size blocks of similar size, for example, a number of 1 MB data blocks. An MD5 hash value is generated from the contents of each block. Each block is written to a file having a filename that includes a filesystem-compliant form (e.g., hexadecimal form) of the computed MD5 hash value. A backup device includes a directory hierarchy having a plurality of first-level directories corresponding to the first two bytes of the hash value, and a plurality of second-level directories corresponding to the next two bytes of the hash value. The blocks are uniquely stored in the directory corresponding to the byte value pairs of the hash. The present disclosure provides data integrity checking and reduces storage requirements for duplicative, redundant, or null data.

Dependencies are inferred from the claim text.