I recently upgraded to Mountain Lion. I am also running the latest Parallels Desktop for Mac, running Windows 7 as a guest OS. So far, so good. However, I've noticed one thing regarding Power Nap and network connectivity. If the Windows 7 guest OS is downloading a large amount of data (i.e. constant network traffic, and disk i/o), and I leave the Mac alone, it will still go to sleep, dropping the network connection in the process. This results in the download of the data failing. Currently, under System Preferences, Energy Saver: Computer sleep is 10 minutes. Display sleep is 10 minutes. "Put hard disks to sleep when possible", "Wake for network access", and "Allow power button to put the computer to sleep" are all checked. The 4th option, "Start automatically after a power failure" is NOT checked. I do not recall ever making changes in previous versions of the Mac OS. I could be wrong. Any ideas/advice would be appreciated. Thank you.
Let me rephrase my original question... I discovered my iMac is too old to support Power Nap. What it all boils down to is this: Why does Mountain Lion put my Mac to sleep even when there is disk and network activity from the Windows VM? If there is a large download on the VM, I can walk away then come back to find the download failed because ML put my Mac to sleep, which includes dropping the network connection. Any advice or thoughts will be appreciated. Thank you.
