I have been happy since I bought my Mac Book Air but I realized that its disk was running out of space, so I have checked various files and directories on it. I found that /private directory had over 6.0 GB (including some swapfiles) and there were a file called sleepimage on /private/var/vm (The real one was on /var/vm), which was 4.0GB.
I investigated what was the sleepimage, I found out that it seemed to be the one that was used for hibernate mode of OSX, which was a temporary reserved for physical memory.
Based on some information in the Internet, it seems to be that when the battery is running out, the contents of the physical memory is backed up in the sleepimage file (/var/vm/sleepimage) temporarily, after that, OS goes down.
My decision is to make the hibernate mode off and remove sleepimage file. That’s it. Because I don’t care whether the work-in-progress files are recovered when the battery goes down. I believe that I am going to just power on or reboot!
I am Happy to get an additional 4.0 GB!
$ sudo pmset -a hibernatemode 0 $ sudo rm /var/vm/sleepimage
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