原文来自：http://macperformanceguide.com/Mac-optimize-sleepimage.html
原文很长，其实。。。集中起来就那么几句话：
1、sudo pmset hibernatemode 0
2、sudo rm -rf /private/vm/sleepimage
当然删除了之后，会有一些问题，是什么呢？是这个啦：
Warning:
(1) With Hibernate on a laptop computer disabled, any unsaved work will be LOST if the battery power runs out, because memory will not be written to disk.
(2) Turning Hibernate off on a laptop is NOT a recommendation per se, but rather an advanced technique for users wishing to squeeeze out more drive space, and find the side effect in (1) acceptable.
如果你并不是特别在意内容的丢失，或者你一直有电，就不用管它了。。