How do I recover from Ubuntu crash?
I am relatively new to Linux but have been enjoying the experience, until today when I accepted an upgrade to Ubuntu 15.04. Hitches occurred and apps didn't open as expected. After using 'sudo apt-get update' and then 'dist-upgrade' lines of script flooded the screen for an interminable period, which was expected, but they terminated with a final line reading as follows:
[ 10.514810] drm_kms_helper@ panic occurred, switching back to text console.
Since that time the computer has frozen and it won't reboot or switch off! I have the preceding fourteen lines of script which might help to identify the problem.
Any expert advice would be much appreciated.