Safe Sleep

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Newer Macintosh laptops (MacBook, MacBook Pro) use an updated sleep feature called Safe Sleep. When users close the comptuer, Safe Sleep writes the RAM contents to the hard drive before the machine actually goes to sleep. During this process, which can last between 30 and 60 seconds, it is recommended that users not move the machine, because this could corrupt the data being written or cause data to be written to an unintended location. The machine is ready for transport when the sleep light starts pulsating.

Disable Safe Sleep

Please note that disabling Safe Sleep will also disable the ability to hot-swap a battery while the machine is sleeping.

1. In the top menubar, click Go, and select Utilities.
2. Find the Terminal application, and double-click to open it.
3. Enter the following command to disable Safe Sleep,

 sudo pmset -a hibernatemode 0

4. Enter the following command to enable Safe Sleep,

 sudo pmset -a hibernatemode 3

5. Enter an administrator password when prompted.


Related Links:

 About Safe Sleep