Multiple drives can be placed into an
external enclosure and brought
wherever needed, making a very cost
effective and portable storage system.
The workings on a hard disk are
simple. Each disk is comprised of a
number of platters which are like smaller, metallic CDs. Platters have a magnetic coating and are accessed by applying
a magnetic field from a rapidly moving
read/write head. Increasing the storage
capacity while keeping the physical size
of the drive the same involves the ability to write data at ever decreasing sizes,
the ability to include more platters per
drive, or a combination of the two.
Manufacturers will state that the
drives are only intended for three to five
years of use. This is because the miniature parts can only withstand so many
start and stop cycles before breaking
down and colliding with the platters.
The manufacturer’s warranty usually is
set to an average time where the possibility of this failure would rise above 50
percent. At that point, collisions begin
to cause decreases in speed, as well as
failing sectors on the disk.
general timeframe on life expectancy.
For frequent backups as well as
storage of small file types, Flash drives
are the ticket. Their portability and
ruggedness is also very appealing.
Flash memory can refer to data
storage such as memory cards, memory sticks, USB drives, jump or thumb
drives, and others. Flash drives have
no moving parts and data is stored
through the electronic circuits inside.
USB devices have a universal
format, however, a Flash card from a
smaller digital camera may not be
readable through a laptop or cell
phone without an adapter.
Flash memory also begins to wear
out after a certain number of cycles.
As this number is reached, read, write,
and general access times will become
that accessing the data requires the
physical insertion of a specific disk (as
with any form of removable media).
When deciding between these two
options, consider factors such as capacity needed, frequency of archives, and
accessibility to stored data.
Bigger Storage Options
Recently, optical disks have been
a shaky area for data archiving
because of the rapidly evolving and
changing formats. Someone who
placed a large amount of data on CDRs must now re-archive the data onto
DVD-Rs. Although it’s nice to need
less disks, it does take time to set up
new equipment and transfer the data.
An optical disk has data literally
burned into it by a laser where hard disks
have data magnetically written. This
technology results in the ability to store
more data in the same physical space.
Manufacturers initially claimed the
stability of optical disks upwards of
100 years, but this may not be a valid
assessment. To be fair, in a perfect
world where your data disk is stored in
a dark, dry, and untouched place (
basically hermetically sealed), it would last
a century or more. In the real world,
light, heat, and movement all contribute to the degradation of the data
stored. Since different types of dye
and materials that all affect lifetimes
are employed, it’s impossible to cast a
Regular computer users who
constantly need to back up data or
keep a large archive have a couple
options to consider: the hard disk
array and the optical disk library.
Just as the name implies, the hard
disk array takes the form of a number of
hard disks. Network Attached Storage
(NAS) units are stand-alone enclosures
and are currently available on the market.
All of the data is always connected
to your computer system, so it can be
searched and replaced very easily. A
potential downside to this setup is that
if a drive becomes corrupted or fails, all
the data may be lost — thus the
creation of RAID, a redundant array
of inexpensive disks. There are many
forms but the basic idea is to cleverly
duplicate the data over other physical
drives, thus allowing a single drive
failure to be recoverable.
An optical disk library takes the
form, not too surprisingly, of a collection of optical disks. You would need
an optical disk drive attached to the system to be archived and then the proper number of disks to handle the data.
The upside to this option is the
low cost of the disks. A blank disk is
well under a dollar. A downside is
As new technologies become available to store more data in less physical
space, the cost to store data will drop.
Research in areas of chemistry and
physics will mix with advances in
digital, electronic, and mechanical
engineering to bring even more dynamic advances in data storage.
One such area already in research
labs is a three-dimensional holographic
storage. This device aims to start at a
storage density of 200 GB per cubic inch
and eventually max out above 10,000 TB
per cubic inch ... all while keeping its
cost equal to today’s top hard disks.
Also in the works are molecular
memories which use special compounds to store electric charges that
represent data; basically a chemical
Flash drive although with much higher
capacity and density. These advances
along with the continued development
of larger capacity disks (some consumer
models boast 750 GB) and optical disks
which can store 50 GB, promise to keep
sizes smaller and prices lower, so you
will get more bang for your buck.
Whatever course data storage
takes, it is working hard to keep up
with other areas of advancing technology because as the world moves
forward, the need to store and recall
data will continue to grow. NV
August 2007 69