HP StorageWorks DAT 72 keeps DDS alive and well

When Sony decided in 2001 to stop R&D for DDS (Digital Data Storage), the announcement caused concern among IT managers who faced the unpleasant task of labeling those archive media and drives as a legacy.

Luckily, users of DDS — a tape format that Hewlett-Packard developed in cooperation with Sony — can take a deep breath because HP has released the first DDS 5 (generation five) unit. The HP StorageWorks DAT 72 houses a single tape drive that shows improvement in capacity while maintaining the form factor, performance, and affordability of its DDS 4 predecessors.

Keeping the tape checked

The DAT 72 meets the performance of its forbears, sustaining transfer rates as fast as 3MBps. By using hardware compression, that rate can jump even higher; in my tests, I clocked backups faster than 7MBps using compression-friendly files and high block size.

As with all tape drives, however, real-life performance will be substantially lower. For instance, when backing up typical user files (a mix of spreadsheet, word processor, and graphic documents), I recorded transfer rates between 2MBps and 3MBps. Your results may vary depending on environmental conditions, such as the responsiveness of server disks and the unique content of your volumes.

What remains constant is the capacity. By extending tape length from 120 meters to 170 meters, the DAT 72 can store as much as 36GB on each cartridge, reducing backup and restore time for large volumes. If your data compresses well, you can double that capacity.

Moreover, existing customers can count on backward compatibility with DDS 3 and 4. In addition, DAT 72 promises the same reliability of DDS 4 models, with a MTBF (mean time between failure) of 400,000 hours at 12-percent usage. I find it interesting that the unit comes with a three-year, next-business-day replacement policy, a warranty you can upgrade (albeit at extra cost) for more stringent business requirements.

Part of the bundle is also a one-license copy of Yosemite Tapeware backup software, but HP anticipates that support from vendors such as Computer Associates, IBM Tivoli, Legato, and Veritas will follow shortly.

Running for recovery

For this review, I received a desktop version of the DAT 72, which measures 4 inches by 4.5 inches by 9 inches and has a front slot for feeding the media and LEDs to show power and tape status. The back of the unit hosts the SCSI and power connectors and the on/off button. As an alternative, you can order internal or rack-mountable DAT 72 versions and group as many as three units on each rack shelf.

Connecting the unit to the server was easy. I chose the tape SCSI ID using a selector in the back of the unit, connected the LVD/SE cable, and powered up. The small cartridges (3 inches by 2 inches) insert easily and almost entirely into the slot. I liked the smooth and quiet media handling, but the cooling fan is rather noisy — its humming can be distinctly heard several feet away.

I had no problem installing the DAT 72 drivers on Windows 2000 and Windows 2003 machines, and the unit ran flawless backups and restores with both the Windows backup application and our copy of Tapeware. Another useful feature of the DAT 72 is its capability of turning into a bootable device to execute OBDR (one-button disaster recovery) procedures, which simplifies the restoring of corrupt OS volume content.

I found it difficult not to like the HP StorageWorks DAT 72. The compact unit is easy to install and operate on many platforms, is reasonably fast, and has good capacity. Future development plans for this tape line have not been made public, however, which could push companies with more demanding expectations to seek alternatives.

Still, HP’s initial DDS 5 offering provides the increased capacity and excellent support options that make it an easy, inexpensive solution to your enterprise storage needs.