According to the log, there seem to be problems with the sda disk (disk may be dying). Also, are you using the XFS filesystem on any of your partitions? If so, this may be related to bug # 8058
-- Could not install GRUB (hd0) https://launchpad.net/bugs/64592 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
