Compaq Computer Corporation, Inc.

Steven E Boone

Steven J Peters

A system, method and computer program product for hardware assisted backup for a computer mass storage subsystem wherein files to be backed up from a source storage medium (e.g. disk) to a formatted storage medium (e.g. tape) are written in logical block number (&ldquo;LBN&rdquo;) order regardless of the file's on-disk layout. If the source file structure information is available it is used or the disk blocks containing the file structure are marked in a used (or &ldquo;free&rdquo;) block bit map which may then be modified to exclude files that are &ldquo;open for write&rdquo;, marked as &ldquo;no backup&rdquo; or not part of the selected file save operation. In operation, the blocks are written to tape using a Tape Copy Data (&ldquo;TCD&rdquo;) command. Blocks that were selected, but excluded as &ldquo;open for write&rdquo; may then be written to the tape utilizing more conventional methodologies. Where possible, the entire disk volume is locked during the backup operation, however, individual files may be selectively locked if all of the files are not being saved. In those instances where the size of any group of contiguous data blocks is too small to be efficaciously backed up, unmarked blocks may also be included in the transfer to speed operation.

System, method and computer program product for hardware assisted backup for a computer mass storage system

A system and method for hardware assisted formatted data transfer allows a formatting storage controller to read and record data on a formatted storage medium and avoids a requirement of continuous interaction by a host system in the transfer process. The host system can initiate the transfer process by sending a command block, a data definition, and an on-media structure definition to a formatting storage controller, which performs the formatted transfer and notifies the host system when the transfer is completed or an exception occurs. Alternately, the formatting storage controller can access one or more on-media structure definitions stored in a persistent storage unit in accordance with an on-media structure selector provided by the host system in the command block. In alternative implementations, the system and method of the present invention allows for the performance of a &ldquo;verify copy&rdquo; operation which causes the formatting storage controller to compare the formatted data recorded on the formatted storage medium with the data stored on an alternate storage medium (e.g. a source or destination storage medium) and a &ldquo;formatted read&rdquo; operation, which causes the formatting storage controller to read the formatted data stored on the formatted storage medium and transfer it to a destination storage medium. Further disclosed is a program product for recording data on a formatted storage medium in accordance with an on-media structure definition initiates a transfer process in accordance with a command block provided to a formatting storage controller.

Hardware assisted formatted data transfer system having a source storage controller and a formatting storage controller receiving on-media structure definition and a data definition

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Monument, CO, United States of America

Steven E Boone