The DAT-DDS Tape Technology

The Digital Audio Tape DAT technology is the most- DAT/DDS tape drives
prolific of all tape technologies. The DAT tape was- DAT/DDS tape autoloaders
previously known as DDS Digital Data Storage. Over- DLT/SDLT tape drives
15 million DAT drives have been shipped since the- LTO Ultrium tape drives & blades
first products were introduced in 1989 and more than- DVD RW optical drives The DAT160 media is just a
6 million since 2000. This gives rise to a conservativewider version of the DAT40 media using MP Metal
estimate of a 6-million user installed base. The HPParticle technology 150 m in length. This is the same
StorageWorks DAT160 tape drive is the latesttype of tape as has been shipping since 1994 in
edition to the DAT family. It was launched by HP inDAT40 cartridges. It has a proven track record of
June 2007. The DAT-160 drive is an evolution ofreliability. However, in DAT160 media, wider version
existing DAT technology and has much in commonof the tape has been used to enable greater
with the previous five generations of DAT. It iscapacity. A DAT160 drive accepts both sizes of
estimated that there are over 6 million DAT tapemedia but threads them around the drum in different
drives currently installed worldwide. The DAT mediaways.
tape cartridge is the Low-cost media and provides itsTransfer rate on DAT technology is determined
customers the lowest cost of ownership.partly by the wrap angle (amount of tape wrapped
The HP StorageWorks DAT 160 tape has 80-GBaround the rotating helical scan drum) and the speed
native capacity and up to 160 GB with 2:1 dataof rotation of the drum. The wrap angle of the
compression. The HP DAT-160 has a transfer rate ofDAT160 drive is 180 degrees compared to only 90
6.9 MB/sec native, over 13.8 MB/sec with 2:1 datadegrees for previous generation DAT technologies,
compression. The DAT160 provides approximatelyso the DAT-160 drive actually makes more efficient
160 GB backing up in under 4 hours. Higher capacityuse of tape in contact with the head to increase
can be achieved mainly by using wider tape fortransfer rate. Further generations will increase the
DAT160, but still provides backward write and readdrum speed.
compatibility with DAT72 and DAT40 media. This canThe HP approach of using independent tape threading
be done by having two independent threadingmechanisms was the breakthrough that enabled the
mechanisms and tape paths inside the device.DAT160 drive to write and read DAT-72 and DAT-40
DAT 160 supports HP StorageWorks One Buttonmedia. When the concept of loading two different
Disaster Recovery Solution when used with theheights of cartridge with two different tape widths
relevant software and HP ProLiant servers, allowingwas invented, HP used extensive computer simulation
total rebuild of a server from a single backup tape. Ittechniques to model the tape threading and routing
also includes Single Server Edition of HP Datafor each tape type. The results of these simulations
Protector Express backup/recovery and disasterindicated that the design concepts were both
recovery software. DAT-160 media cartridge ispractical and yielded good levels of margin in allowing
supported on a wide range of operating system andthe design to be successful.
backup applications.The most difficult challenge has been accommodating
Enterprise backup compatibility (EBS)all the mechanical components in the physical space
- Enterprise (E-Series) librariesavailable. However, using the HP standard product
- Virtual (VLS) librariesdesign and testing methodology, the necessary
- Business (MSL) librariesmechanical solutions and enhancements have been
- 1/8 G2 tape autoloadersevolved. The robust engineering and margin in these
- 1/8 tape autoloaderstape guides are the keys of a successful interchange.
Tape Backup compatibility