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There 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 overvoltages 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. |