In past few months, I am facing an irritating problem with my macbook pro which crashes almost right after I start moving files from one hard disk to another. In this case, I have one external USB powered hard disk, one external powered external disk and one SSD hard disk attached. Whenever I move data from 2nd hard disk to SSD disk, the hard disks gets ejected (2nd and 3rd) and within few seconds, macbook freezes for few seconds and then it reboots. This has happened over a dozen times and it's irritating.