I have set hibernate mode to 25 and the standby time to 0 in macOS Mojave. Now my idea is that the Mac goes to deep sleep (no power to RAM). Most of the time it works; if I open the lid I see this screen:

Picture: wake up from deep sleep

But sometimes I have to press the power button to start the Mac. Either it starts as I would have turn it off before. Or (more often) it starts for a second (with start sound) and then turns black and starts again (again start sound).

I read something about "dark wake". So may be the problem is, that the Mac wakes up. But I don't know how to prevent that.

Any ideas? Or maybe a better setup to secure the system (in-fact prevent the encryption key from FileVault to be in the RAM when I close the lid)?

My setup is:

  • I have one user only for Disc encryption (other users are deleted with: sudo fdesetup remove -user username)
  • DestroyFVKeyOnStandby = 1
  • standby = 0
~$> pmset -g
System-wide power settings:
 DestroyFVKeyOnStandby      1
Currently in use:
 standbydelaylow      0
 standby              0
 halfdim              1
 hibernatefile        /var/vm/sleepimage
 gpuswitch            2
 powernap             0
 disksleep            0
 standbydelayhigh     0
 sleep                0 (sleep prevented by cloudd, cloudd, sharingd)
 autopoweroffdelay    28800
 hibernatemode        25
 autopoweroff         1
 ttyskeepawake        1
 displaysleep         0
 highstandbythreshold 50
 acwake               0
 lidwake              1
  • Do you have the T2 chip? I couldn't make this work on 2018 MacBook Air. Waking from Standby (hibernate 25), login screen appeared, followed by kernel panic after entering pwd. KPs were related to the T2 chip. I have not found a config that works as you desire. I suspect T2 isn't compatible with DestryoyFVKeyOnStandby. "On Mac systems with the T2 chip, all FileVault key handling occurs in the Secure Enclave; encryption keys are never directly exposed to the (Intel) application processor." apple.com/mac/docs/Apple_T2_Security_Chip_Overview.pdf – Jonathan Dagle May 5 at 13:21

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