Liebert UPS PowerSure PSA and Mac OS X

I recently acquired a very nice UPS for my home network (we have a lot of thunderstorms over here), the Liebert PowerSure PSA 1000VA/650W. The UPS management software Multilink is of course optimized for Windows operating systems. I contacted the Liebert support to find out which alternatives are available for Mac OS X.

My main question was about the recommended way to notify Mac OS X computers with events sent by the Liebert UPS for doing safe shutdowns or monitoring UPS load. In my home environment, the UPS is connected via USB to a dual boot Linux/Windows machine because of the system requirements of the UPS management software (which has a lot of nifty features but runs best on Windows). There are ready-to-run client applications for receiving and acting upon UPS notifications but, alas, they are not available for Mac OS X.

Here is the response of one of Liebert’s application engineers:

Unfortunately we don’t have anything better than the USB support for Mac power management at this time. The best option we have seen for a totally Mac environment is to connect the UPS via USB, and within the built-in power management configure it to send shutdown indication to other computers via SSH or some other network means. For a completely network based situation, the toolkit NET-SNMP can be used to react to on battery or low battery traps, but this requires some shell scripting in order to work in an orderly way.

So if you happen to use Mac OS X in combination with a Liebert UPS, you should prepare to do some console hacking. “Just works” won’t work (sic!) here for Macs. A good starting point is Interfacing a Contact-Closure UPS to Mac OS X and Linux, an informative report written by David Hough (last updated on June 23, 2005).