Travan Versus Onstream SLR Tape Drive

Quarter-Inch Cartridge (QIC) | O-MaSS | Minicartridge | DLTtape | Super DTLtape (SDLT) | Linear Tape-Open (LTO) | Half-Inch Cartridge | StorageTek 9840/T9840B/T9940 | Helical-Scan Technologies | 4-mm Helical Scan Digital Audio Tape/Digital Data Storage (DAT/DDS) | 8-mm Helical Scan Mammoth Technology | VXA Technology | Advanced Intelligent Tape (AIT) Technology | S-AIT

Minicartridge
Drives in this category are based primarily on Imation's Travan technology and Advanced Digital
Recording (ADR) technology from OnStream Data. Imation Corporation introduced Travan in 1995 and
currently partners with Seagate Removable Storage Solutions (RSS) to develop drives based on this
technology. OnStream's technology has its foundation in the Philips Digital Compact Cassette (DCC)
audio tape player, which Phillips originally brought to market in 1993. ADR was created by leveraging the
DCC technology along with other research and development that was done by Philips Electronics.

Travan technology, which is based on linear recording technology, is closely related to quarter-inch
standards. It leveraged proven minicartridge technology that existed prior to its introduction in December
1994, and it maintained backward compatibility with the installed base of drives. But it did represent a
major advancement in the technology because it was based on a unique drive/cartridge interface
developed by 3M. At the heart of the new technology was a new-shaped cartridge that optimized the
amount of tape area for cartridges that could fit in a 3.5-inch form factor tape drive. Data is recorded along
the length of the tape with a static read/write head, and drives use single-channel recording and a simple
tape path with only two moving parts in the drive. Unique to Travan drives is the track-positioning system
with prerecorded servo patterns at both ends of the tape. Through accurate electronic servo signal
detection and digital signal processing, the track-positioning algorithm positions the head to the optimal
location relative to the data tracks on the tape. When the read/write head is correctly positioned at the
beginning of the tape, it is locked into position. A precision tape guidance system built into the Travan
data cartridge prevents the tape from wandering.
Seagate and Imation remain committed to extending Travan technology capacity and performance, and in
March 2002 the two companies announced the availability of a new family of sixth-generation Travan
drives, called Travan 40. This new technology extends the native storage capacity to 20GB (40GB with
2:1 data compression) with a native data transfer rate of 2 MB/sec (4 MB/sec when operating in
compressed mode) while maintaining backward read compatibility with 10GB (native) Travan 20 drives.
The Travan 40 uses Seagate's FastSense technology, which adjusts the speed of the tape drive to match
system throughput. FastSense keeps the tape in a streaming mode of operation, helping to optimize
backup times. A number of other design enhancements were also added to the Travan 40, including a
steel frame for improved durability, a soft-load mechanism to reduce normal wear and tear, and a thermal
monitor that activates firmware throttle-down features when drive temperatures reach perdetermined
levels. A VR2 data channel was also incorporated to enable higher recording densities, and a park feature
that ensures the alignment of recording tracks if a write operation is suspended was added.
OnStream's ADR is based on a variable-speed, digital tape storage technology with two distinguishing
features that differentiate it from competitive technologies.
o
Spatially Distributed Error Correction Code (ECC)-ADR makes use of spatially distributed ECC,
meaning that error correction bits are recorded over all eight tracks simultaneously so information can
be recovered even if an entire track is lost. OnStream rates the drive error rate at one lost bit in every
1,019 bits written.
o
Full Tape Servo-An advanced embedded servo system contributes to high data reliability in two
ways: first by communicating with the head to assure media integrity as it writes data, and second by
preventing the tape from wandering off track, which could make the data unreadable in the future.
OnStream's second-generation ADR drive, the ADR2 120Si, uses a SCSI-3 LVD/SE Ultra-2 compatible
interface and is positioned for use with entry-level servers and workstations. It supports 60GB of native
capacity (120GB with compression) and data transfer rates up to 4 MB/sec (8 MB/sec with 2:1
compression).