Linux: Configure and Control APC SmartUPS During a Power Failure

APC SmartUPS is a line of uninterruptible power supply (UPS) devices that can provide backup power to a system during a power failure. On a Linux system, you can use the apcupsd daemon to monitor and control an APC SmartUPS.

To configure and control an APC SmartUPS on a Linux system, follow these steps:

1. Install the apcupsd package:

On a Debian-based system, you can use the following command to install apcupsd:

sudo apt-get update
sudo apt-get install apcupsd

On an RPM-based system (like Fedora or CentOS), you can use the following command:

sudo yum install apcupsd

On a SUSE-based system (like openSUSE), you can use the following command:

sudo zypper install apcupsd

2. Configure the apcupsd daemon:

The apcupsd daemon is configured through the /etc/apcupsd/apcupsd.conf file. You can edit this file to specify the UPS device and configure various options. Here's an example configuration file:

UPSCABLE smart
UPSTYPE apcsmart
DEVICE /dev/ttyS0

BATTERYLEVEL 15
MINUTES 3

ONBATTERYDELAY 6

NETSERVER on
NISIP 0.0.0.0
NISPORT 3551

EVENTSFILE /var/log/apcupsd.events
EVENTSFILEMAX 10

UPSCLASS standalone
UPSMODE disable

This configuration specifies a Smart UPS connected through a serial port (/dev/ttyS0), with a battery level threshold of 15% and a shutdown delay of 3 minutes. It also enables the apcupsd daemon to listen for network connections and sends notifications to the specified IP address and port.

3. Start the apcupsd daemon:

To start the apcupsd daemon, use the following command:

sudo systemctl start apcupsd

To start apcupsd automatically on boot, use the following command:

sudo systemctl enable apcupsd

4. Monitor the UPS status:

You can use the apcaccess command to view the status of the UPS. For example:

apcaccess status

This will show the current battery level, load, and other status information for the UPS.

5. Perform actions during a power failure:

You can configure the apcupsd daemon to perform various actions during a power failure, such as shutting down the system or running a script. To do this, you can edit the ONBATTERY and LOWBATT options in the apcupsd.conf file. For example:

ONBATTERY powerfail
LOWBATT shutdown

This will cause the system to initiate a powerfail shutdown when the UPS switches to battery power, and to initiate a shutdown when the battery level reaches the low battery threshold.