Network UPS Tools User Manual

Network UPS Tools User Manual 29 / 84
6.4 Typical setups for enterprise networks and data rooms
The split nature of this UPS monitoring software allows a wide variety of power connections. This chapter will help you identify
how things should be configured using some general descriptions.
There are two main elements:
1. There’s a UPS attached to a communication (serial, USB or network) port on this system.
2. This system depends on a UPS for power.
You can play "mix and match" with those two to arrive at these descriptions for individual hosts:
• A: 1 but not 2
• B: 2 but not 1
• C: 1 and 2
A small to medium sized data room usually has one C and a bunch of Bs. This means that there’s a system (type C) hooked to
the UPS which depends on it for power. There are also some other systems in there (type B) which depend on that same UPS for
power, but aren’t directly connected to it.
Larger data rooms or those with multiple UPSes may have several "clusters" of the "single C, many Bs" depending on how it’s
all wired.
Finally, there’s a special case. Type A systems are connected to a UPS’s serial port, but don’t depend on it for power. This usually
happens when a UPS is physically close to a box and can reach the serial port, but the wiring is such that it doesn’t actually feed
it.
Once you identify a system’s type, use this list to decide which of the programs need to be run for monitoring:
• A: driver and upsd
• B: upsmon (as slave)
• C: driver, upsd, and upsmon (as master)
To further complicate things, you can have a system that is hooked to multiple UPSes, but only depends on one for power. This
particular situation makes it an "A" relative to one UPS, and a "C" relative to the other. The software can handle this - you just
have to tell it what to do.
Note
NUT can also serve as a data proxy to increase the number of clients, or share the communication load between several upsd
instances.