Name: Typical setups for data rooms
File: data-room.txt
Date: 19 August 2000
Auth: Russell Kroll <rkroll@exploits.org>

The split nature of this UPS monitoring software allows a wide variety of
power connections.  This document 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 serial 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: model driver and upsd
B: upsmon (as slave)
C: model 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.

Multi-power supply boxes
========================

Previously this was handled by running multiple instances of upsmon and
other ugliness.  Fortunately 0.44.0 now has native support for multiple
UPS monitoring built into upsmon.  See big-servers.txt for more details.
