23. Why doesn’t upsmon shut down my system? I pulled the plug and nothing happened.

Wait. upsmon doesn’t consider a UPS to be critical until it’s both on battery and low battery at the same time. This is by design. Nearly every UPS supports the notion of detecting the low battery all by itself. When the voltage drops below a certain point, it will let you know about it.

If your system has a really complicated shutdown procedure, you might need to shut down before the UPS raises the low battery flag. For most users, however, the default behavior is adequate.

Ask yourself this: why buy a nice big UPS with the matching battery and corresponding runtime and then shutdown early? If anything, I’d rather have a few more minutes running on battery during which the power might return. Once the power’s back, it’s business as usual with no visible interruption in service.

If you purposely shut down early, you guarantee an interruption in service by bringing down the box.

See upssched.txt for information on how you can shutdown early if this is what you really want to do.