I installed Ubuntu 12.04 on a RAID1 array a few months ago and explained it all here: http://permalink.gmane.org/gmane.user-groups.linux.tclug/20855 I have been running Unity on the box but I normally attach to it via VNC (with IceWM) in an SSH tunnel. A few days ago the VNC session hung on me and the Xvnc process was at 100% CPU. I had to kill it. (Probably a known bug, but I'll skip that story for now.) Before starting it up again, I ran update-manager from the console. I could see that there was something seriously wrong with Unity -- the task bar on the side had only one item in it, that was just a grayed out box, and it was unresponsive. After running update-manager I rebooted. I don't know what the exit status was for update-manager because it was gone and I don't know if it did much. After rebooting, I have this error: error:invalid magic number error:you need to load the kernel first Grub will show some options for other kernels. I have tried some, and none of them will boot. They hang with a bunch of info on the screen. Any ideas on how to proceed? What tests should I be doing to find the source of the problem? Thanks in advance. Mike