Machine check exception
Jul 9 12:19:41 vz01 kernel: CPU 0: Machine Check Exception: 0000000000000004 Jul 9 12:19:41 vz01 kernel: Bank 4: b604a00100000813 at 000000007e4f2f68 Jul 9 12:19:41 vz01 kernel: Kernel panic: CPU context corrupt
Such messages are printed when CPU reports about detected hardware problems, e.g. memory corruptions or some other problems. i.e. it is 100% hardware problem with your server. http://www.answers.com/topic/machine-check-exception
You can try to check your memory/CPU as decribed here: http://wiki.openvz.org/Hardware_testing