Hi. I've rolled back my guest to 10.9.2 to temporarily solve the grey screen/spinning cog on boot up dilemma until Parallels fixes it. I don't think this has anything to do with my issue, though..... I set up my VM with a 64 GB disk allocation, checking the option to allow for auto expansion. I started getting alerts (on the VM) that my startup disk was close to full (and it was), so its not expanding. There is plenty of space on the host drive on my imac (i'm using about 1 TB out of 3 TB total). Any idea how to get the auto expansion to work? I also have a windows VM, and I suppose the same problem will eventually rear its ugly head there too. Thanks in advance for any assistance Kenny in New Jersey