相关疑难解决方法(0)

我想知道为什么upgrade有时不想升级系统的某些部分，而dist-upgrade确实如此。这是运行后的示例apt-get upgrade：

apt-get upgrade：

rimmer@rimmer-Lenovo-IdeaPad-S10-2:~$ sudo apt-get upgrade
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following packages have been kept back:
  linux-generic linux-headers-generic linux-image-generic
0 upgraded, 0 newly installed, 0 to remove and 3 not upgraded.

与apt-get dist-upgrade：

rimmer@rimmer-Lenovo-IdeaPad-S10-2:~$ sudo apt-get dist-upgrade
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Calculating upgrade... Done
The following NEW packages will be installed:
  linux-headers-3.0.0-13 linux-headers-3.0.0-13-generic
  linux-image-3.0.0-13-generic …

我正在运行 Ubuntu 14.10，系统磁盘用 luks 加密。当我启动计算机时，它显示 Ubuntu 徽标并要求输入密码以解锁磁盘。但是，我无法输入密码。如果我输入密码并按 Enter 键，则不会发生任何事情。不过，我可以打Ctrl+ Alt+Del重新启动计算机。目前启动计算机的唯一方法是使用恢复模式。

有任何想法吗？