Apple - Turn off Macbook automatic hibernation mode?
From a Terminal, use the following command to disable hibernation:
sudo pmset -a hibernatemode 0
If you later want to enable hibernation, use:
sudo pmset -a hibernatemode 3
If you want to free up the disk space used by hibernation, use the following command:
sudo rm /var/vm/sleepimage
- Note: This file is automatically recreated as needed if hibernation is reenabled and it doesn't already exist.