Sep 222010
 

I have been looking into a problem with my Macbook Pro for quite a while now – despite setting the preferred sleep mode with sudo pmset -a hibernatemode 1, the laptop refuses to go into hibernate mode. It doesn’t even go into hibernate mode when the battery runs down sufficiently that it should do.

This leads to a couple of problems :-

  1. On occasions, the battery runs down enough to loose all power meaning my laptop switches off, and all running programs are terminated.
  2. Also the laptop sometimes comes out of sleep mode in my backpack getting very hot in the process.

According to a comment on a blog posting, there may be an issue with Firefox preventing hibernation from working – why that should be, I haven’t the faintest idea. Despite seeming a touch unlikely, I gave it a go – quitting Firefox and then putting the laptop to sleep.

And it hibernates!

However it turns out that stopping Firefox doesn’t prevent my main machine from hibernating. After a long hunt and several experiments, it turns out that OSX will simply not hibernate to a disk that isn’t in the slot where the hard disk is. Or in other words, you cannot hibernate when your boot disk in an SSD in the ExpressCard slot.

Which strikes me as a bit … weird. I guess the fix for this would be a proper SSD in the hard disk slot and to move the hard disk elsewhere.

After having invested in an SSD and spent far too long forcing my tired old eyes to operate in my MBP, I can confirm that hibernation does work with any kind of disk in the right slot for the hard disk.