Configuring apcupsd on Linux for Multiple USB UPSes

I recently needed to add monitoring of a UPS powering network equipment to a Linux server already monitoring one USB-connected UPS. Since the second UPS also uses a USB connection for monitoring apcpusd (the standard UPS management package for Linux systems) was not seeing it. This is not a fault of the software – it’s designed to work pretty much seamlessly with detection of a single UPS and does so, but autodetectin multiple battery backups would still require some level of manual configuration – at the very least, which one(s) are powering the monitoring system in case it needs to shut down? The solution is to set up udev rules to let the system recognize each attached UPS as a distinct device using the serial number of the UPS, then follow the instructions for managing multiple UPSes in the manual. Continue reading Configuring apcupsd on Linux for Multiple USB UPSes