iMac randomly wakes up and how to fix it

My iMac randomly wakes up. I never noticed it until DropCam caught it in action. How do you resolve this? This forum thread helped. These are notes for myself so that I remember what to do whenever I update OS X to a new version.

1. Goto Settings. Click on "Energy Saver".
2. Make sure "Wake for network access" is unchecked.
3. Make sure "Enable Power Nap" is unchecked.
4. Bring up Terminal. If you don't know how to do this, click the Spotlight Search icon (magnifying glass in upper right corner of desktop), and type "Terminal" (without the quotes). Open the Terminal app.

5. Inside Terminal, type the following command to determine how often your computer wakes.
   pmset -g log | grep Wake

This command will print how often your Mac has woken up and for what reasons. It will list all of the times your Mac has woken up. Mine said the following:

...

2014-12-11 09:07:01 -0800 DarkWake            DarkWake [CDN] due to RTC/Maintenance: Using AC                            46 secs   

2014-12-11 09:07:01 -0800 Kernel Client Acks  Delays to Wake notifications: [BNBMouseDevice driver is slow(msg: SetState to 1)(310 ms)] [AppleBluetoothHIDKeyboard driver is slow(msg: SetState to 1)(310 ms)] [en0 driver is slow(msg: DidChangeState to 2)(716 ms)] [AppleAHCIDiskQueueManager driver is slow(msg: SetState to 3)(5190 ms)]           

2014-12-11 09:07:49 -0800 Wake Requests       [*proc=discoveryd request=Maintenance inDelta=6478]           

2014-12-11 10:55:52 -0800 DarkWake            DarkWake [CDN] due to RTC/Maintenance: Using AC                            45 secs   

2014-12-11 10:55:52 -0800 Kernel Client Acks  Delays to Wake notifications: [AppleBluetoothHIDKeyboard driver is slow(msg: SetState to 1)(372 ms)] [BNBMouseDevice driver is slow(msg: SetState to 1)(373 ms)] [en0 driver is slow(msg: DidChangeState to 2)(716 ms)] [AppleAHCIDiskQueueManager driver is slow(msg: SetState to 3)(5207 ms)]           

2014-12-11 10:56:39 -0800 Wake Requests       [*proc=discoveryd request=Maintenance inDelta=6478]           

2014-12-11 12:44:42 -0800 DarkWake            DarkWake [CDN] due to RTC/Maintenance: Using AC                            45 secs   

2014-12-11 12:44:42 -0800 Kernel Client Acks  Delays to Wake notifications: [BNBMouseDevice driver is slow(msg: SetState to 1)(308 ms)] [AppleBluetoothHIDKeyboard driver is slow(msg: SetState to 1)(308 ms)] [en0 driver is slow(msg: DidChangeState to 2)(715 ms)] [AppleAHCIDiskQueueManager driver is slow(msg: SetState to 3)(5183 ms)]           

2014-12-11 12:45:29 -0800 Wake Requests       [*proc=discoveryd request=Maintenance inDelta=6478]           

2014-12-11 14:33:32 -0800 DarkWake            DarkWake [CDN] due to RTC/Maintenance: Using AC                            45 secs   

2014-12-11 14:33:32 -0800 Kernel Client Acks  Delays to Wake notifications: [BNBMouseDevice driver is slow(msg: SetState to 1)(342 ms)] [AppleBluetoothHIDKeyboard driver is slow(msg: SetState to 1)(342 ms)] [en0 driver is slow(msg: DidChangeState to 2)(714 ms)] [AppleIntelAzulController driver is slow(msg: SetState to 2)(1056 ms)] [AppleAHCIDiskQueueManager driver is slow(msg: SetState to 3)(5191 ms)]           

2014-12-11 14:34:19 -0800 Wake Requests       [*proc=discoveryd request=Maintenance inDelta=6478]           

2014-12-11 16:22:22 -0800 DarkWake            DarkWake [CDN] due to RTC/Maintenance: Using AC                            46 secs   

2014-12-11 16:22:22 -0800 Kernel Client Acks  Delays to Wake notifications: [en0 driver is slow(msg: DidChangeState to 2)(715 ms)] [AppleAHCIDiskQueueManager driver is slow(msg: SetState to 3)(5188 ms)]           

2014-12-11 16:23:10 -0800 Wake Requests       [*proc=discoveryd request=Maintenance inDelta=6478]           

2014-12-11 18:11:13 -0800 DarkWake            DarkWake [CDN] due to RTC/Maintenance: Using AC                            45 secs   

2014-12-11 18:11:13 -0800 Kernel Client Acks  Delays to Wake notifications: [en0 driver is slow(msg: DidChangeState to 2)(716 ms)] [AppleAHCIDiskQueueManager driver is slow(msg: SetState to 3)(5174 ms)]           

2014-12-11 18:12:00 -0800 Wake Requests       [*proc=discoveryd request=Maintenance inDelta=6478]           

2014-12-11 18:43:01 -0800 Wake                Wake [CDNVA] due to XHC1/HID Activity: Using AC                                      

2014-12-11 18:43:01 -0800 Kernel Client Acks  Delays to Wake notifications: [AppleHDADriver driver is slow(msg: SetState to 1)(405 ms)] [en0 driver is slow(msg: DidChangeState to 2)(704 ms)] [AppleHDADriver driver is slow(msg: SetState to 1)(468 ms)] [AppleAHCIDiskQueueManager driver is slow(msg: SetState to 3)(5184 ms)]           

Total Sleep/Wakes since boot at 2014-12-09 21:04:10 -0800 :26

This also explains why my wireless keyboard and mouse batteries keep dying so quickly. 

6. Check your power management settings. In Terminal, type the following:

   pmset -g

This command prints the current power management settings:

Active Profiles:

AC Power -1*

Currently in use:

 standby              0

 Sleep On Power Button 1

 womp                 0

 halfdim              1

 hibernatefile        /var/vm/sleepimage

 darkwakes            0

 autorestart          0

 networkoversleep     0

 disksleep            10

 sleep                1 (sleep prevented by nsurlsessiond, nsurlsessiond, nsurlsessiond, storeassetd, storeassetd)

 autopoweroffdelay    14400

 hibernatemode        0

 autopoweroff         1

 ttyskeepawake        1

 displaysleep         15

 standbydelay         10800

I've bolded/highlighted the two settings that are referenced in the thread. These should both be zero. If not, you can override the settings as follows (you'll need to have administrator rights). Type the following in Terminal to set autopoweroff to 0:

  sudo /usr/bin/pmset autopoweroff 0

And to set standby to 0:

  sudo /usr/bin/pmset standby 0

The sudo command lets you run the command as an administrator. It will ask you for your password to run the command in administrator mode. You must have administrator rights to the machine for this command to work.

Then verify in Terminal with:

  pmset -g


7. Check tomorrow if your system randomly wakes up. If it persists, you'll need to dig deeper for what other possible reasons (e.g. USB device drivers plugged in that could be triggering a wake)