How to store sleepimage on secondary HDD on Mac OS X 10.6?

Question

I have a MBP 2010 with Snow Leopard on it. I put an SSD in the place of DVD Drive and am using an awesome SSD(80GB)+HDD(500GB) combo for speed and efficiency for the right price.

All I want to do is store the sleepimage on the HDD rather than the SSD since I have 8GB RAM and I can't afford to use 8GB SSD to store the current state of my Mac. Looked for a plist to make this change but failed. Not even sure if this can be done.

I have smartsleep pref pane in case anyone is wondering. It is a handy tool(setting) but I want the state to be stored if possible!

Thank you guys!

Answer 1

Nice HDD setup!

Load Terminal.App in the utilities folder, and use the following command:

sudo pmset -a hibernatefile /Volumes/OtherVolume/sleepimage

Obviously change /OtherVolume/sleepimage to /YourOtherVolumesName/sleepimage

From explanatorygap.net.

(EDIT: that webpage shows even the author did not succeed with this method. Likely reason is the other drive is not ready to read the image when trying to wake up. Apple says the sleepimage must be on the root drive. I myself am getting a crash when trying this.)

Answer 2

Mac's normal sleep do not have a sleep image, only "Safe Sleep" or hibernate incurs one.

As far as I know, hibernate is useful to prevent slow boot-ups; i.e., a fast restore from hibernate is preferable to a slow boot-up.

Since you've transition to SSD, this is no longer true. SSD boot-ups are in the low teens of seconds (typically 12-15 secs), so unless restore from hibernate can beat that, I don't see much point of hibernate.

Answer 3

I tried locating the sleepimage in the HDD and booting from the SSD in a firewire enclosure. It worked perfectly. I use sleep very often, like 5 times a day at least. I don't want to be writing 40GB of info in my SSD every day since it will shorten its life. We will se if it's reliable with the SSD installed on the DVD bay. If not, I'll just write

sudo pmset -a hibernatemode 0

on the terminal so I get a plain sleep mode both with battery and AC power, trying to avoid running out of power while sleeping (the computer and myself).

Answer 4

This worked perfectly for me on 10.10.3 (MBP early 2011):

sudo pmset -a hibernatefile /Volumes/OtherVolume/sleepimage

I created a path on the 2nd SSD to complete the above command "/Volumes/HD2/var/vm/sleepimage".

I have my lidwake turned off so that I have to hit the spacebar to turn the comp on. This might have "helped" with the timing of things, but I didn't have any issues.

Only thing I experienced was that I had encrypted HD2, so when the comp ran out of juice and was restarted, it could not access HD2 until I had put the encryption key in which resulted in a full restart instead of from hibernation image.

Moving the sleepimage to another disk improved my time-to-sleep by minutes ( no joke ). I have the original onboard Apple SSD (older 3 Gigabit link speed) which was taking forever to save the 8 GB sleepimage but now with the image on HD2 @ 6 Gigabit link speed, sleep is back to a few seconds.