Novell NETWARE 6-DOCUMENTATION Manual page 2838

Using an Uninterruptible Power Supply (UPS)
An uninterruptible power supply (UPS) is a backup power unit that supplies
uninterrupted power if a commercial power outage occurs. A UPS is an
indispensable part of your network. Not only does it help prevent damage to
your computers from power surges and brownouts, but it also prevents data
loss during power outages.
Both online and offline UPS systems are available:
Online UPS actively modifies the power as it moves through the unit. If
a power outage occurs, the unit is already active and continues to provide
power.
An online UPS is usually more expensive than an offline UPS, but
provides a nearly constant source of energy during power outages.
Offline UPS monitors the power line. When power drops, the UPS is
activated.
The drawback to this method is the slight lag before the offline UPS
becomes active. However, most offline UPS systems are fast enough to
offset this lag.
Because UPS systems can be expensive, most companies attach them only to
the most critical devices, such as NetWare servers, routers, and hard disk
subsystems.
Attaching a UPS to a server enables the server to properly close files and
rewrite the system directory to disk.
Unfortunately, most programs run on the workstation and data stored in RAM
is not saved during a power outage unless each station has its own UPS.
If the UPS doesn't have its own form of surge protection, install a surge
protector to protect the UPS.
Managing the NetWare Server
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