启动时确定域名的问题

Question

从昨天开始，当 Ubuntu 启动时，我的系统显示以下错误消息：

Starting redis-server: redis-server.
speech dispatcher disabled; edit /etc/default/speech-dispatcher
 * Starting vnStat daemon vnstatd                                             [ OK ]
saned disabled; edit /etc/default/saned
 * Starting web server apache2
apache2: Could not reliably determine the server's fully qualified domain name,
using 127.0.1.1 for ServerName
                                                                              [ OK ]
 * Checking battery state...                                                  [ OK ]
 * Starting TiMidity++ ALSA midi emulation...                                 [ OK ]

有时 Ubuntu 可以正常加载。即使过了一段时间后可以正常加载，它也会冻结，下次再出现相同的黑色错误屏幕。每次出现此错误时，启动屏幕颜色也会发生变化，屏幕上会出现一些水平线。