User's Manual

Introduction
3
In data-compression mode, the Seagate DAT 72 and DDS-4 drives typically double
the storage capacity and transfer rate of the native uncompressed operation. Tape
capacity and the sustained data-transfer rate are dependent upon the characteristics
of the files being compressed, the application software used, and system parameters
such as the speed of the host and the operating system. The DAT 72 and DDS–4
drives also offer synchronous or asynchronous SCSI transfers with a high-speed
burst data-transfer rates.
The DAT 72 and DDS-4 drives provide superb reliability through three levels of error-
correction code (ECC) and the four-head design, which provides for read-after-write
(RAW) error detection and correction. The DAT 72 and DDS-4 drives also include a
“flying” preamplifier for greater signal-to-noise ratio.
Features
The DAT 72 and DDS-4 drives represent Seagate’s commitment to reliable
engineering and durable tape drive products that implement leading-edge
technology. Key features of the drives include:
•
A platform based on state-of-the-art sealed drive mechanism and tape-handling
components for improved immunity to airborne contaminants and extended
media life
•
Three available form factors: 3.5-inch internal for installation in a 3.5-inch half-
height space; 3.5-inch drive with factory-installed 5.25-inch mounting rails and
bezel for installation in a 5.25-inch half-height space; and external subsystem
with built-in, auto-sensing, worldwide power supply
•
ANSI/ECMA compliance and capability to write and read DDS 5
th
Generation
(DAT 72 only) DDS-4, DDS-3, and DDS-2 (DDS-4 only) cartridges
•
Advanced onboard DDS-DC hardware using Data Compression Lempel-Ziv
(DCLZ) data-compression algorithm
•
High-speed transfer rates for fast backups
DDS-4:
– 2.75 Mbytes per second typical—uncompressed data
– 5.5 Kbytes per second typical—compressed data
DAT 72:
– 3.5 Mbytes per second typical—uncompressed data
– 7.0 Kbytes per second typical—compressed data
•
High-performance SCSI burst transfer rate of 10 Mbytes per second
asynchronous and 80 Mbytes per second synchronous
•
Flash memory to store setup parameters and enable field firmware upgrades
•
Four-head design with RAW error detection and rewrites
•
Three levels of ECC to ensure data integrity
•
Uncorrectable error rate of less than 1 in 10
15
bits
•
LVD / Ultra Wide SCSI connection
•
Automatic power-on self-test
•
Support for TapeAlert™ Certified Solutions