The Internet Encyclopedia (Volume 3)

P1: JDV

Michael WL040/Bidgolio-Vol I WL040-Sample.cls June 19, 2003 16:10 Char Count= 0

PREVENTIVEMEASURES 77

to be cost-effective. The collapses of the buildings at the

World Trade Center had earthquake-like effects on neigh-

boring buildings. (Even the initial crashes registered on

seismographs.) Because disasters can occur in anyone’s

neighborhood, any structure may be subjected to “seis-

mic” forces.

Regardless of construction techniques, how the occu-

pants furnish buildings is largely their own responsibil-

ity. Some precautions can be taken with relatively little

expense or intrusion to normal operations. Following are

three suggestions from Garfinkel (2002) based on the sim-

ple principle that objects will move and perhaps fall from

high places to lower places:

1. Place computers under sturdy tables, not on high sur-
   faces or near windows.


2. Do not place heavy objects so that they could fall onto
   computers.


3. Restrain the possible movement of computers with
   bolts and other equipment.

The first two recommendations also help in case dam-

aging wind (including the force of an external explosion)

blows out a window or damages a roof. The last could also

serve as a theft deterrent, depending on the type of re-

straint used. There are also relatively easy ways to secure

things other than computers. For example, bookcases can

be bolted to walls so they cannot topple, and books can

be restrained by removable bars or straps.

Ruggedization of Equipment

With the upsurge in mobile computing comes an in-

creased risk of damage from shock, vibration, dust, wa-

ter, and extremes of temperature and humidity. One sur-

vey found that 18% of corporate laptops in “nonrugged”

applications had suffered substantial damage (averaging

about half the purchase price), implying that more people

could benefit from tougher equipment. Laptops and other

mobile devices can beruggedizedby adding characteristics

such as the following:

1. having an extra-sturdy metal chassis, possibly encased
   in rubber;


2. being shock- and vibration-resistant (with a floating
   LCD panel or gel-mounted hard drive);


3. being rainproof, resistant to high humidity and tolerant
   of salt fog;


4. being dustproof (with an overlay panel for the LCD
   screen);


5. being able to withstand temperature extremes and ther-
   mal shock; and


6. being able to operate at high altitude.

Touchscreens, port replicators, glare-resistant coatings

for the LCD screen, and modular components are avail-

able on some models. Some portable ruggedized units re-

semble a suitcase more than a modern laptop.

Ruggedization techniques can also be used for any

computer that must remain in areas where explosions or

other harsh conditions may be encountered. Accessories

available are ruggedized disk drives, mouse covers, key-

board covers, and sealed keyboards. (Some keyboards can

be rolled up.) Some biometric devices can be used in de-

manding environments.

Redundancy

Redundancy is the safety net for ensuring integrity and

availability of resources. Because of the many facets of the

computing environment, redundancy takes many forms.

The first thing that comes to mind is backing up data. If

only a single copy of information exists, it may be dif-

ficult, if not impossible, to reconstruct it with complete

confidence in its validity. Not to be overlooked are sys-

tem software and configurations. They should also be

backed up in such a way that restarting the system or

restoring it to a nominal condition can be accomplished

expeditiously.

There are a wide variety of schemes for creating back-

ups. Most are based on some type of high-density tape. Ca-

pacities for some are measured in terabytes. The backup

procedure can be either manual or automated. The lat-

ter approach is safer because it removes the potential for

human error in the process, but an automated procedure

should issue a notification if it encounters problems while

performing its duties. Backups can be made, managed,

and used remotely. Some systems allow access to other

cartridges while one cartridge is receiving data. Scalabil-

ity is an important feature available. As mentioned earlier,

tapes that are subjected to repeated reuse should period-

ically be tested and, if necessary, cleaned by a tape certi-

fier.

Backups should be kept at a separate location, prefer-

ably far enough away from the site of origin that a sin-

gle storm, forest fire, earthquake, or dirty bomb could

not damage both locations. At a bare minimum, back-

ups should be kept in a fireproof, explosion-resistant safe;

it must include insulation so that heat is not conducted

to its contents. Backups that are going off-site (perhaps

via the Internet) should be encrypted. In all cases, ac-

cess to backups should be restricted to authorized per-

sonnel.

Point-in-time recovery requires not only periodic back-

ups but also continual logging of changes to the data since

the last complete backup so that files can be reconstructed

to match their last version. Although the need to backup

digital information is well recognized, essential printed

documents are sometimes overlooked. These can be con-

verted to a more compact medium (e.g., microfilm).

Redundancy in the availability of power can be

achieved using a UPS (discussed previously). Some sys-

tems themselves have redundant batteries and circuitry.

Nonetheless, most UPS systems have backup times de-

signed only to allow controlled shutdown of the system so

that no data is lost or equipment damaged. For continued

operation during extended blackouts, a backup generator

system will also be necessary. It is tempting to place large

UPS systems and generators in a basement, but that can

backfire if the power outage is concurrent with water en-

tering the building. It is important to anticipate plausible

combinations of calamities.

Telephone redundancy has its difficulties. Cellular

communications should be available in case wired phone