Recently, my MacBook Pro (mid 2012, 15 inch, 10.8.2) has started going into what seems to be hibernate mode after several hours asleep, whether it's plugged in or on battery. When I unplug it, it wakes briefly without me opening the lid (I can tell because the CD drive cycles). If I open the lid, I see it loading the hibernate file before becoming active again.
I looked at the output of pmset -g, and see the following settings that might be relevant to this problem:
lidwake 1 autopoweroff 1 autopoweroffdelay 14400 standbydelay 4200 standby 0 hibernatemode 3 acwake 0
Interestingly, "acwake" is zero, as is "standby". But "autopoweroff" is 1, and the "autopoweroffdelay" is 14400 (4 hours). Looking at the system log from last night, I see these entries:
Nov 26 22:36:28 ITHAA1STHOMAMBP kernel: sleep Nov 27 02:36:30 ITHAA1STHOMAMBP kernel: Wake reason: EC.SleepTimer (SleepTimer) Nov 27 02:36:30 ITHAA1STHOMAMBP kernel: AirPort_Brcm43xx::powerChange: System Wake - Full Wake/ Dark Wake / Maintenance wake Nov 27 02:36:30 ITHAA1STHOMAMBP kernel: Previous Sleep Cause: 5 ... Nov 27 02:36:51 ITHAA1STHOMAMBP kernel: hibernate_page_list_setall(preflight 0) start 0xffffff80de079000, 0xffffff80de0b9000 Nov 27 08:38:21 ITHAA1STHOMAMBP kernel: hibernate_page_list_setall time: 491 ms ... Nov 27 08:38:31 ITHAA1STHOMAMBP kernel: sleep
I put the computer to sleep by closing the cover at 22:36. It woke itself 4 hours later at 02:36 and hibernated. At 08:38 I unplugged the power to bring the laptop to work, and it woke briefly.
What it looks like to me is that the computer is going into auto power down after 4 hours. But there are some things I don't understand:
- Why did this start happening recently (within the last week, as far as I can recall, and not associated with any software update)?
- Why does it wake on power change when "acwake" is 0?
- Can I just set "autopoweroff" to 0?