Keep Your Mac Awake With Caffeine
Tired of your Mac falling asleep when it should be doing your bidding? Maybe you’re running a service on it you need 24/7 access to? Apple seems to be a little too environmentally friendly some days. It’s hard to keep a Mac completely awake – no matter what you do in System Preferences.
I have a VOIP VM that I occasionally run on my iMac. Despite setting my iMac to “never sleep” in its System Preferences, the VOIP server would frequently unregister and cause phone outages because the Mac was going to sleep anyway.
A free program called Caffeine solved my problems. Check it out at the Lighthead website or install it from the App Store. You can easily turn it on or off indefinitely or for an amount of time. It simply and effectively keeps your computer completely awake, display and all, or allows it to keep its normal sleep schedule. Maybe it can help you, too.