I've had my VMs on Hyper-V 2012 (standalone) shutdown/stop randomly. My VMs are all snapshotted images with the modern.ie windows 7 image (barebone windows 7 with IE9) as the base image. I basicly have installed no software, but have a cd/iso that is mounted with the necessary software and a run script that executes on startup
I have 11 VMs w/ 1gb ram each configured identically on a Dell R610 with 1xIntel Xeon E5xx cpu, and 24gb of Ram. The VMs all seem to shutdown around the same time, It seems to happen after they have been running idle for a few hours, so I can't confirm if it's a hypervisor issue or a guest OS issue, but being that they all become 'stopped' around the same time leads me to believe that it's the hypervisor, but again they are identical images and I can't confirm that the Guest OSes aren't doing something that causes them to shutdown.
Basically, where do I start looking to figure out whats causing it? I've had mixed success with connecting to the Hyper-V box with various MMC snap-ins, but I have the HyperV manager and the services manager working (the device manager does not work).