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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 single 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. |
