The Back-hitching Problem. Conventional tape drives are designed to
operate efficiently at a constant tape speed and data transfer rate.
However, the host system seldom sends or receives data at a specific
fixed rate. This is because data is transmitted in bursts that result in
fluctuating transfer rates. Whenever the flow of data is interrupted, the
drive must stop the tape, back it up, accelerate it to the appropriate
speed, and then continue the data transfer in the same orientation as
before. This process, known as back-hitching, reduces the effective data
throughput and can add significant wear and tear to both the tape drive
and to the tapes. Back-hitching seriously impacts data reliability because
these extreme changes in tape direction accelerate wear on the media.
In addition, worn tapes increase the rate of head wear and are a source
of debris and contamination, decreasing mechanism life. These factors
ultimately impact the drives ability to restore data.
Conventional Tapes High Cost. Conventional tape drive
manufacturers have relied on increasingly complex designs to meet
increasing performance and capacity requirements. The architecture of
tracking tape drives grows more and more complex as capacity (track
density) and data transfer rates are increased. They require costly,
complex mechanical and electrical components to combat inherent track-
to-head alignment problems. While conventional tape devices have kept
pace in increasing performance and capacity, they have not delivered to
end-users the same historical price reductions users have come to
expect in other storage mediums like disk storage. Relatively speaking,
tape has become expensive.
VXA Packets -- Breakthrough Technology
Packet Technology breakthroughs enable VXA to provide far superior
data reliability, speed and capacity at a lower cost. VXA is the only
production tape technology in the world to approach tape backup in a
fundamentally different way than the other track-based designs.
VXA Packets Are Fundamentally Better Than Tracks. VXA reads and
writes data in packets, the most reliable and affordable method for
transferring data as is witnessed in modern network and Internet
technology. The drive also employs a variable speed function that has
the ability to match the host data transfer rate, eliminating the back-
hitching that causes job delays and wear on the media and drive
mechanism. Packet Technology also allows for a more innovative and
streamlined design than conventional tracking drives and thus requires
fewer and less expensive parts resulting in a lower cost drive and better
overall reliability.
Packets Alleviate the Head to Tape Alignment Issue. VXA Packet
Technology approaches the biggest problem of tape today, head-to-tape
alignment, by eliminating the need for it in the first place. VXA has
accomplished this by fundamentally changing the way that tape drives
write and read data. Instead of using conventional tracks, VXA uses
digital packets to write and restore data.
To start with, long strings of data are broken into small units of data
packets before being recorded on the media. Each data packet includes
p1
p2
p3
p4
p5
p6