Thursday, May 2, 2013

APC Smart-UPS 1500

Frequent power cuts have caused my dev workstation to restart unexpectedly a few times recently. This isn’t really a problem for individual desktops, but as this machine runs Hyper-V and hosts 20+ virtual machines there’s some small risk that sudden power failure might leave one or more boxes in an inconsistent state leading to some work to repair them once power is restored. Seems like a no-brainer: stick an uninterruptable power supply (UPS) on and do a clean shutdown before the juice runs out.

I’ve not bought a UPS before so was not really sure what to go for. This Dell Precision T7600 chassis is rated for 1300W, but I’ve no idea what it actually consumes or how variable that might be. In the end I got an APC Smart-UPS 1500 for around £500, which reports my current load, for the workstation and one monitor, as around 20% loading giving 80 minutes of battery time.

Windows Server 2008 R2 detected the battery automatically when I connected the UPS to the server via a USB lead and integrates it with power options just like with a Windows laptop. I configured a new power plan and set the critical level to 50% and the action to Shutdown, which is the only one available, expecting this to initiate the same shutdown you get from Start > Shut Down.

I switched the power to the UPS off and the battery took over. After 30 minutes it got to 50% remaining. A crash message window appeared briefly before the server was dropped. It wasn’t a nice Windows shutdown – it just gutted itself!

Upon power restore we get asked the “unexplained shutdown” question and the VMs are “Off” when I was expecting them to be “Saved”. Not good. More Microsoft stuff that doesn’t work out of the box. Worse is that it all looks OK, until you try it.

Fortunately the UPS comes with its own monitoring system, APC PowerChute, which monitors the battery and does do a proper shutdown. It’s just a shame I have to install some vendor-specific crapware to achieve something that Windows can clearly handle itself (if only it were not bugged).

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