Description of problem: upgrade from f15 to f16 failed for kernel panic: not syncing: VFS: unable to mount root fs on unkown block(0,0) Version-Release number of selected component (if applicable): How reproducible: Steps to Reproduce: 1. upgrade f15 to f16 2. reboot system 3. cannot boot into the system, the error occurred as the attachment Actual results: Expected results: Additional info: