I had my MacPro running fine all morning, went out to do some errands and upon my return I noticed that my MacPro was not responding so I proceeded to manually powered it off (watched the beach ball for almost 30 mins before pressing the power button). When the system rebooted I noticed that it booted to my Mavericks SSD instead of the El Cap, I also noticed that my El Cap SSD wasn't showing on the desktop anymore like before. IpProceeded to Disk Utility in Mavericks and the system can see the Apple SSD but it's showing as "unformatted" status, does this mean that I lost all the data on it? Is there anyway to recover from this? Also, I am getting a "The disk you inserted was not readable by this computer" message after booting into Mavericks for 15 mins, gives me the option to initialize, Ignore or Eject. I haven't done anything with this message yet, just left it alone for now until I can find out more on what's going on. Any help is greatly appreciated.