ADIC VLS AIT, Installation And Operating Manual, Page: 18 / 90

4 Getting Started
Equipment Description
The VLS Unit
The VLS AIT
™
is a fully automated, high performance, high capacity, mass storage system
designed with a removable data cassette magazine. The door can be locked to deactivate the
unit's keypad, assuring only authorized removal of the magazine and media. In addition, to
protect the unit, data and media, the VLS will not operate unless the door is closed.
The VLS AIT includes either one or two 3.5” form factor Sony
®
AIT tape drives. The library
and drive(s) operate as separate SCSI devices on a single SCSI bus. When the library is
equipped with AIT-1 drives, the library is a differential SCSI-2 device and the drives are
differential Fast/Wide SCSI-2 devices. When equipped with AIT-2 drives, the library and
drives can be configured as high voltage differential (HVD) Wide Ultra SCSI devices, or as
low voltage differential (LVD) Wide Ultra SCSI devices.
When operating with two AIT-2 tape drives and assuming an average data compression ratio
of 2:1, the VLS AIT can store up to 1.1 Terabytes of information on 11 AIT-2 data cassettes
(SDX2-50C). It can reach a sustained maximum data transfer rate of over 720 MB per minute
(also assuming 2:1 compression). The AIT-1 or AIT-2 tape drives do not require periodic
head cleaning as often as many conventional tape drives. The drive constantly monitors head
output to check for possible contamination. If present, the drive will invoke a built-in Active
Head Cleaner. Under extreme operating conditions, a cleaning cartridge may be required and
the drive indicates this by displaying a Cleaning Request message on its front panel Status
LED.
The Sony SDX1-25C, SDX1-35C, SDX2-36C, and SDX2-50C data cassettes support the
Advanced Intelligent Tape (AIT) format, Adaptive Lossless Data Compression (ALDC),
Memory In Cassette (MIC
™
) technology capabilities and use Sony’s AME
™
media, which
incorporates dual cobalt magnetic layers, the absence of binder material tp prevent tape head
contamination and a super-durable “diamond-like carbon” protective coating for extreme
durability.