I've had my Mac Mini for about six months now. Every night, I put it to Sleep rather than shutting it down. Since about two weeks ago, the Mac Mini wakes up from sleep around 1 to 3 am, once a night, and then after about 10 seconds, it puts itself back to sleep. Why does it do this? Is it performing some sort of maintenance function? But that then begs the question, why is it only doing this recently, and not a few months ago?
I checked the Console for messages, and there's roughly the same thing every night. Here's part of what appears in the logs, particularly whatever pertains to waking from sleep (let me know if you need me to post a specific snippet):
Sep 14 02:00:30 gary-mac kernel: AppleThunderboltNHIType2::waitForOk2Go2Sx - retries = 6 Sep 14 02:00:30 gary-mac kernel: IOThunderboltSwitch<0xffffff8048e40000>(0x0)::listenerCallback - Thunderbolt HPD packet for route = 0x0 port = 12 unplug = 0 Sep 14 02:00:30 gary-mac kernel: TBT W (2): 0x0100 [x] Sep 14 02:00:30 gary-mac kernel: Wake reason: EC.SleepTimer (SleepTimer) Sep 14 02:00:30 gary-mac kernel: AirPort_Brcm43xx::powerChange: System Wake - Full Wake/ Dark Wake / Maintenance wake Sep 14 02:00:30 gary-mac kernel: Previous Sleep Cause: 5 Sep 14 02:00:30 gary-mac kernel: The USB device USB 3.0 HUB Sep 14 02:00:30 gary-mac kernel: (Port 1 of Hub at 0x15000000) may have caused a wake by issuing a remote wakeup (1)
I'm sure there's something useful in there (such as references to the USB ports) but I can't exactly figure them out. For your information, my Mac Mini has four USB ports, and all four are used. USB port 1 is an external drive, USB port 2 is an external drive, USB port 3 is connected to a KVM, which provides access to my mouse and keyboard, and USB port 4 is connected to a USB 3 hub that splits the port into four other ports.
When I go to the System Information app to determine what device is at USB location 0x15000000, I get the following:
USB 3.0 HUB: Product ID: 0x0812 Vendor ID: 0x2109 (VIA Labs, Inc.) Version: 85.71 Speed: Up to 5 Gb/sec Manufacturer: VLI Labs, Inc. Location ID: 0x15100000 / 3 Current Available (mA): 900 Current Required (mA): 0
It just looks like a generic device of some sort. Right above this device in the System Information app is the first USB device I have connected, which is my external drive for Time Machine. Could that be the problem somehow, even though its device location is
0x15400000 / 4?
Could this problem be due to the recently released Mac OS X 10.8.5? It seems like the problem started occurring a few days after the update was released. I have already performed the basic maintenance of resetting the SMC and PRAM, and Repairing Disk Permissions, but that didn't fix the problem. Also, in the System Preferences -> Energy Saver page, I've got all checkboxes UNchecked (including "Wake for network access"). I haven't had any other wake issues since this started happening. Plus, the fact that the Mac Mini goes back to sleep after a few seconds doesn't seem to indicate that it could possibly be a network access problem, or a mouse randomly moving, right?