Abstract: A first volume comprising a plurality of blocks stored in a first location is accessed. A plurality of hash values representing the plurality of blocks is stored. The plurality of blocks is copied to a second volume stored in a second location, generating a copied volume. The copied volume is verified based on the plurality of hash values. In one embodiment, the first volume is altered, after the plurality of hash values is stored. Altering the first volume may include changing data in a selected one of the plurality of blocks. The first volume may be altered during copying of the plurality of blocks to the second volume.

Abstract: A data packet is generated. An instruction relating to a selected data processing operation, and information indicating that additional processing of the data packet is required, are inserted into the data packet. For example, the information may comprise a predetermined bit or a predetermined sequence of bits. In one embodiment, the information is inserted at a predetermined location within the data packet. The data packet is inserted into a selected field of an iSCSI command. For example, the data packet may be inserted into a buffer field of the iSCSI command. The iSCSI command is transmitted.

Abstract: A first volume comprising a plurality of blocks stored in a first location is accessed. A plurality of hash values representing the plurality of blocks is stored. The plurality of blocks is copied to a second volume stored in a second location, generating a copied volume. The copied volume is verified based on the plurality of hash values. In one embodiment, the first volume is altered, after the plurality of hash values is stored. Altering the first volume may include changing data in a selected one of the plurality of blocks. The first volume may be altered during copying of the plurality of blocks to the second volume.