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will tape wind up?
bells-and-whistles each technology proponent is pushing,
capacity and speed are the two main criteria CIOs look at
when comparing tape storage alternatives available today
format tape technology has been time-tested and market proven
to have a long lifespan that is key for data protectioN.
The mechanical simplicity of linear technology means there
are few moving parts, providing durability and lower maintenance
study released by UC Berkeley's School of Information Management
and System last year estimated that between one to two exabytes
(1018 bytes) of unique data is produced each year. Put another
way, it is roughly equivalent to 250 MB of data
for every man, woman and child on earth!
The next question is naturally, how is all this data being
stored? About 80 percent of all this data is stored digitally,
with the remainder in print form or on film. With new information
being created every single day,
organizations have to find cost-effective ways to store
and backup their data, with the ability to retrieve quickly
Over 40 and going strong
Tape storage was invented by IBM scientists in 1952, and
has proved to be one of the most enduring technologies the
industry has seen. Today, tape remains the preferred media
for backup and recovery because of its lower cost per megabyte,
reliability and durability.
The evolution of the tape storage technology has received
a boost in recent years from a few quarters. For a start,
while the dotcom bubble has burst, the momentum created
by the era is propelling the world into the information
age like never before. This in turn is leading to a trend
of building Storage Area Networks (SANs) to provide centralized
management of diverse storage resources through the network.
Finally, the introduction of new tape formats like Linear
Tape Open (LTO) addressing the limitations of existing technology
has reassured CIOs that tape remains a reliable, affordable
and viable technology for their company's back-up needs.
Back up a minute
An industry rule of thumb suggests that there is about 10
times as much storage on tape as on hard drives. According
a recent International Data Corporation study on the tape
drive market, 4.5 million tape drives will be shipped in
Linear format tape technology has been time-tested and market
proven to have a long lifespan that is key for data protection.
The mechanical simplicity of linear technology means there
are few moving parts, providing proven durability and lower
But whatever bells-and-whistles each technology proponent
is pushing, capacity and speed are the two main criteria
CIOs look at in comparing the alternatives available today.
Capacity: With data growing as fast as it is, companies
are putting pressure on storage vendors for more capacity
in the same form factor. For example, the DLT format that
dominates the market today offers only 40 GB native capacity
(80 GB compressed). This means more cartridges are required
and more precious IT man-hours spent manning the drives,
removing and inserting new cartridges .
Speed: Depending on the industry and company, backup can
be done daily or weekly. It is usually done in the middle
of the night as the business applications being backed-up
usually had to be brought down for this purpose. The faster
the data transfer rate of a tape solution, the shorter will
be the backup window
and downtime-a major plus
in an age of 24-hour-a-day customer service.
A comparison of LTO and Super
One of the main drivers pushing tape vendors is the demand
for very large and shareable data repositories brought on
by e-business and SAN.
With this comes a corresponding need to be able to retrieve
data backed-up on tape as quickly as possible. In a situation
where a company has suffered the catastrophic loss of its
data on primary server drives, the speed at which its business
can get up and running again is absolutely dependent on
the speed at which its data can be retrieved.
IBM-Hewlett Packard-Seagate's Linear-Tape Open (LTO) and
Quantum's Super DLT represent the two most advanced tape
technology formats available today.
Capacity: Today, Quantum's Super DLT tape cartridge boasts
the higher capacity of the two with 110 GB native capacity
compared to LTO's 100 GB. However, the only product available
today is the Quantum Super DLT 220 that offers a single
tape drive with a single cartridge. The LTO family today
offers a range of products from a one drive/one cartridge
product to an ultra-scaleable tape library which can contain
up to 72 drives and 496.2 TB compressed capacity.
Quantum has promised that future generations of Super DLT
will deliver up to one terabyte of capacity and a 100 MB/second
data transfer rate. Today, the LTO consortium has
already unveiled a clearly
defined four-generation roadmap that will see its capacity
doubling with each generation to 200 GB (by 2002), 400 GB
and 800 GB in the next few years.
Speed: As the saying goes, this is where the rubber hits
More important than the capacity is the speed to backup
and restore the data. Allowed time frames for backup are
becoming shorter, and the data rate is becoming one of the
leading factors for choosing a tape technology.
Here LTO has an edge over Super DLT with a 15 MB/second
uncompressed data transfer rate over the latter's 11MB/second.
In tests run with two typical back-up scenarios where 200
GB and 800 GB of data have to be written in 2 hours, LTO
demonstrated its superiority
Because of the higher data rate of IBM LTO Ultrium, in each
case it was found that fewer drives and therefore
lower costs were needed to backup the specified amount of
data in a defined time.
An independent data recovery exercise run by the IT Manager
for CMP Asia, a global publishing house, they found that
with IBM's LTO solution,
they were able to shorten the backup window by 25 percent,
to their previous experience with DLT.
The Eddy Group, a US utilities
company, was similarly impressed by LTO. "We wanted
more speed than we had, but this is astounding. Now, a full
backup takes just five minutes down from over two hours."
Competition is a healthy state of affairs for the industry.
It keeps vendors on their toes to keep pushing the technology
Which is why the goal of the LTO Consortium to offer a truly
open standard that supports data interchange among multiple
vendors' products is a laudable one. A choice of vendors
and a clearly defined roadmap endorsed by the top
storage companies can only mean good news for customers.
Where will tape wind up? Everywhere.
Sandeep Dutta is the Country Business Manager,
Storage, IBM India and can be reached at firstname.lastname@example.org.
(The opinion expressed in thisarticle is the author's own)