Removing FileVault2 key from memory on lid close

Solution 1:

In addition to the destroyfvkeyonstandby option, you also need to specify that pmset is setting hibernatemode 25 for the power management options.

sudo pmset -a destroyfvkeyonstandby 1 hibernatemode 25

Setting both options ensures that the Mac in question will hibernate (where the contents of the RAM are written to disk) and also have the FileVault 2 key automatically removed from the saved RAM.

When the laptop is awakened from hibernation, you should see your account icon and a password blank at the FileVault 2 login screen, which would indicate that it had been asleep.

When this setting is set, you may run into some Power Nap-related issues. I have a post on that available from here:

Power Nap, power management settings and FileVault 2