I own a mid 2012 macbook pro OSX yosemite with RAID 0 of 2 x samsung 840 evo 250gb. My laptop froze when I tried to log in, and now I get the gray screen with circle/slash through after I restarted. I tried the disk utility startup and one of my raid slice was shown as missing, and that drive was not showing up at all. I checked all connections and now that drive shows up as an unformatted disk. Is it possible to make it recognize that it's the missing RAID slice? I have not done anything that would reformat/erase the disks. I don't know too much about these stuff, so please let me know what other information I need to provide. I'm also assuming the drive is working properly, but I don't really know how to check it.