Portability. For an effective Disaster recovery plan companies must keep a copy of their data at a remote offsite location. In terms of portability, data storage
tapes are still the most valuable method for providing off-site data storage.
Data storage tape technologies
Discussed below are some of the industries' most popular open standard formats which
have a clear migration path, ensuring backwards compatibility.
Travan or QIC
With capacity range from 20-40 GB, Travan NS (Network Series) data backup tapes
for tape libraries and stand alone enjoys a widespread acceptance for computer backups. Travan mechanisms are known to be very reliable at a low cost point and are the
perfect choice in the standalone personal computer arena and in entry-level server
backup applications.
4mm digital audio tape (DAT) or digital data storage (DDS)
The DDS is based on helical-scan technology and are primarily aimed at departments
using workgroup server applications where backups are not regularly taken and the
time window for doing so is small. Both the drive and the media offer compact form
factors which make these drives popular for using in small autoloaders. Tabulated
below are characteristic features of various available DDS data tapes.
|
Recording formats
|
Capacity
|
Data transfer rate
|
|
DS
|
4 GB
|
366 kps
|
|
DS-2
|
8 GB
|
1 MBps
|
|
DS-3
|
24 GB
|
2MBps
|
|
DS-4
|
40GB
|
3 MBps
|
The fate of DDS is clear, as manufacturers have expressed their inability to scale
up DDS format beyond the current DDS-4 version within that form factor.
DLT/SuperDLT:
DLT is regarded as the "king of the tape backup market" with an installed based
of over 2.2 million drives to date. The attractiveness of DLT is based on its long
durability combined with its high
capacity. The new DLT 8000 is replacing the popular
DLT 7000 and the older DLT 4000. DLT 8000 offers raw capacity of 40 GB and a transfer
rate of 6 MBps.
SuperDLT was introduced in 2001 and is the most recent of Quantum’s tape product.
Super-DLT uses LGMR(laser-guided magnetic recording) technology to produce better
performance, higher capacity and more safer DLT drives.
The first SuperDLT generation devices offer a raw capacity 110 GB per cartridge
and a transfer data rate of 11 MB/second, while still providing as an option backward
compatibility with the DLT4000, 7000 and 8000 tape products. Quantum is adopting a multi-generational migration strategy for the SuperDLT technology which will produce
drives with 1 TB capacity and with transfer data rates of 100 MB/second.
LTO (Linear Tape Open)
LTO drives are relatively common in the storage data tapes market.
By using linear tape technology the LTO includes the latest in data compression,
ECC and head technology it adopts an open data tape storage architecture offering high scalability and high reliability for tape drives of the future. LTO comes of
two formats: one a high-capacity format based on the Ultrium and the other is the
Accelis fast-access design. The 1st generation LTO Ultrium format offers native
capacity of 100 GB per cartridge and up to 16 MB/sec data rate. The LTO consortium
has announced already a clearly defined roadmap for their four-generation LTO that
will see with each generation its capacity doubling.
Advanced Intelligent Tape (AIT)
AIT 8mm magnetic tape storage format developed by Sony, uses the company's Memory
in Cassette (MIC) architecture. The MIC includes a memory chip which is used to
stores the log of the system and other user information.
By using MIC, Sony has been able to reduce load times. AIT can now store up to 65GB
with transfer data rates of up to 7.8MBps (compressed) for its data backup tapes.
The new AIT-2 drive includes 50 GB of raw capacity, 100 GB compressed, with a raw
data transfer rate of 6 MBps which is about the same as that of the DLT 8000 drive.
Sony’s plan for the AIT project is a doubling of its capacity and of the throughput
rate every two years.