Network UPS Tools User Manual

Network UPS Tools User Manual 4 / 84
2.8.4 UPS Shutdowns
upsdrvctl can also shut down (power down) all of your UPS hardware.
Warning
if you play around with this command, expect your filesystems to die. Don’t power off your computers unless they’re
ready for it:
/usr/local/ups/sbin/upsdrvctl shutdown
/usr/local/ups/sbin/upsdrvctl shutdown sparky
You should read the Configuring automatic UPS shutdowns chapter to learn more about when to use this feature. If called at the
wrong time, you may cause data loss by turning off a system with a filesystem mounted read-write.
2.8.5 Power distribution unit management
NUT also provides an advanced support for power distribution units.
You should read the Configuring automatic UPS shutdowns chapter to learn more about when to use this feature.
2.9 Network Server
upsd is responsible for passing data from the drivers to the client programs via the network. It should be run immediately after
upsdrvctl in your system’s startup scripts.
upsd should be kept running whenever possible, as it is the only source of status information for the monitoring clients like
upsmon.
2.10 Monitoring client
upsmon provides the essential feature that you expect to find in UPS monitoring software: safe shutdowns when the power fails.
In the layered scheme of NUT software, it is a client. It has this separate section in the documentation since it is so important.
You configure it by telling it about UPSes that you want to monitor in upsmon.conf. Each UPS can be defined as one of two
possible types:
2.10.1 Master
This UPS supplies power to the system running upsmon, and this system is also responsible for shutting it down when the
battery is depleted. This occurs after any slave systems have disconnected safely.
If your UPS is plugged directly into a system’s serial port, the upsmon process on that system should define that UPS as a
master.
For a typical home user, there’s one computer connected to one UPS. That means you run a driver, upsd, and upsmon in master
mode.
2.10.2 Slave
This UPS may supply power to the system running upsmon, but this system can’t shut it down directly.
Use this mode when you run multiple computers on the same UPS. Obviously, only one can be connected to the serial port on
the UPS, and that system is the master. Everything else is a slave.
For a typical home user, there’s one computer connected to one UPS. That means you run a driver, upsd, and upsmon in master
mode.