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T
here are two unfortunate
realities of the electronics age;
the utility simply cannot provide the clean, consistent power demanded
by sensitive electronics, and the customer is ultimately responsible for
the health and safe operation of his equipment.
A study by IBM has
showed that a typical computer is subject to more than 120 power problems
per month. The effects of power problems range from the subtle
keyboard
lockups, hardware degradation to the dramatic
complete data loss or burnt
motherboards. According to a survey by the Yankee Group, almost half of
the corporations researched put their downtime costs at upwards of $1,000
per hour, with nine percent estimating costs up to or more than $50,000
per hour.
Clearly, businesses are becoming more and more reliant on
a utility power supply that is pushed beyond its capacity. Despite
advances in the capabilities of modern personal computers, a momentary
power outage is still all it takes to lose your data. More dangerous is
the loss of previously written files, or even an entire hard disk, which
can occur should a power problem strike while your computer is saving a
file. Network fileservers constantly writing to disk are particularly
susceptible.
Unfortunately the situation won't be getting better
anytime soon. It takes approximately a decade to get a new power
plant on-line, and concerns about nuclear power and fossil fuels have
stifled the construction of new generating facilities. In the United
States, for instance, spending on utilities has dropped from 2.3% of
the Gross National Product in the 1960's to less than 1% today.
It's been said that there are two types of computer users: those who
have lost data because of a power problem, and those who are going to.
Over the past few years, we've helped create a new class... those who
have recognized the need for protection and taken steps to ensure that
they're prepared for the inevitable.
Power problems are the largest cause of data loss
Power Failure/Surge: 45.3%
Storm Damage: 9.4%
Fire or Explosion: 8.2%
Hardware/Software Error: 8.2%
Flood & Water Damage: 6.7%
Earthquake: 5.5%
Network Outage: 4.5%
Human Error/Sabotage: 3.2%
HVAC Failure: 2.3%
Other 6.7%
Source: Contingency Planning
The anatomy of a power disturbance
Surges, spikes, blackouts and brownouts...what really happens to your computer
when it experiences an out-of-bounds power anomaly?
We'll use a nearby
lightning strike as an example, although it is just one of countless problems
that can strike your system. Lightning strikes a nearby transformer.
If the surge is powerful enough, it travels instantaneously through wiring,
network, serial and phone lines and more, with the electrical equivalent force
of a tidal wave. The surge travels into your computer via the outlet or phone
lines. The first casualty is usually a modem or motherboard. Chips go next,
and data is lost. The utility responds to over-voltages by disconnecting
the grid. This creates brownouts and blackouts. If the voltage drops low enough,
or blacks out, the hard disk may crash, destroying the data stored on the disk.
In all cases, work-in- process stored in cache is instantly lost. In the worst
case, password protection on the hard drive can be jumbled, or the file allocation
table may be upset, rendering the hard disk useless.
Copyright 1995, 1996, 1997,
1998, 1999 American Power Conversion Corporation (APC), 132 Fairgrounds Road,
West Kingston, Rhode Island 02892 U.S.A. All rights reserved.
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