Remove "sleepimage" and get many GBs back and faster sleep!

[qwerty123]

I recently used CCC to clone my main OS drive only to notice that it copied only about 37gb of the 70gb on my OS drive. I was so puzzled about this. Then I discovered the culprit: a 34gb sleep image file that CCC doesn't copy... but as soon as I booted into my clone drive, the file appeared and the clone was bloated to the 70gb drive size.

But here's the kicker: for desktops, you don't really need that sleep image file! The file is generally about the size of the RAM you have installed on your system (mine is 32gb RAM)... So you could easily get this space back. On top of that: my computer goes to sleep instantly now rather than waiting a while to do so (as it has to write the sleep image file anew when you go to sleep with sleep image enabled or "safe sleep").

There's a previous thread started asking about whether it's ok to do this here: http://www.tonymacx86.com/general-help/85674-safe-disable-safe-sleep.html ...But I thought this was a significant enough gain to point it out with a separate thread!

Here's the guide I followed: http://www.maclife.com/article/howtos/how_remove_diskhogging_sleepimage_file_your_mac

And here's some useful reading on this function: http://www.tuaw.com/2011/08/22/why-hibernate-or-safe-sleep-mode-is-no-longer-necessary-in-os/

To remove the sleep image file:

sudo rm -rf /var/vm/sleepimage

To disable safe sleep mode:

sudo pmset hibernatemode 0

Happy hacking!

 

[MrEddy]

Thanks for pointing this info !
Since have 32GB or RAM and a 256GB SSD as my system disk, it's very helpful to keep those 32GB free

 

[DBP]

qwerty123, I thought you would have read my build posts where I mention this.

This is such a simple trick to save lots of space (and only laptops really benefit from hibernate mode 3) that everyone who discovers it is usually very excited about it.
Actually, I've been using this on my MacBooks for years so that when I close the lid the machine goes to sleep almost immediately without spending time writing out RAM to disk. The only risk then is that if the battery runs down completely during sleep that I'll lose everything and have to reboot, but that risk has been worth it for me. Even with the newer laptops with SSDs the saving is faster, but as MrEddy mentions every gigabyte is precious on a laptop SSD.

 

[mike5065]

i would add: sleep will write 16GB (for me) to your SSD, that will most likely never be used, and wear down your SSD faster.

 

[qwerty123]

qwerty123, I thought you would have read my build posts where I mention this.

Ha! Only saw your posts after I discovered (that other people had discovered) this. I'm surprised more people don't post doing this. It really does make a big difference especially if your boot drive is an SSD and you've got a lot of RAM!

Many cheers to you for including this in your build guides!

 

[tonymacx86]

Great work everyone- we're going to add this to the next MultiBeast. Sleep and wake seem instantaneous now.

Here are before and after shots showing that I regained disk space:



Edit: This is done automatically in MultiBeast now

 

[Bimmer325Ci]

Maybe add Chameleon SSD Optimizer to Multibeast. It a program like Trim Enabler but with more options, like the ones discuss below.

 

[archelon]

Here's something from that Mac Life article needs to be considered before deleting the "sleepimage" file:

"When you start your machine back up, your Mac will perform a normal reboot without restoring windows, and opened files."

 

[cem2ran]

It should perhaps be noted that instead of actually storing whatever is in your RAM on your HDD it instead remains on the RAM. This has the consequence of your machine booting up once in a while to retain the state of the RAM. So if you actually shut off for your power source to your machine this is not the way to go. I myself have been using this "trick" for quite a while as I only have 128gigs of SSD storage and the trade-off is therefore minimal. And it's also a no-brainer if you actually don't use the sleep functionality...

Kudos for bringing it up though, I'm sure a lot will benefit from it!

 

[sundanc3]

Wow! this is interesting and exciting because I have 8GB of RAM and only a 32GB boot SSD. All the extra space is greatly appreciated!