我不是服务器专家，所以我遇到了Ubuntu的一些升级问题。 有一点历史：我的数字海洋水滴运行Ubuntu 12.04 LTS，然后几个月前，我升级到一个新的HWE继续接受12.04的安全更新。 最近我把Ubuntu升级到14.04 LTS。 一切似乎工作正常，除非我没有收到任何通知，有包要更新。 login到我的服务器后，“今日讯息”继续显示：
0 packages can be updated. 0 updates are security updates. 现在不可能正确的3个星期…？
运行sudo apt-get update运行没有错误和sudo apt-get upgrade说0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
我有一种感觉，我的/etc/apt/sources.list升级到新的HWE核心，然后是新的LTS后，不知何故损坏了。 以下是目前列出的来源。 有没有人看到这个列表的任何问题？ 任何意见，将不胜感激。
$ cat /etc/apt/sources.list # # deb cdrom:[Ubuntu-Server 12.04.3 LTS _Precise Pangolin_ - Release i386 (20130820.2)]/ precise main restricted # See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to # newer versions of the distribution. ## DigitalOcean mirrors for blazing speed! deb http://mirrors.digitalocean.com/ubuntu/ trusty main restricted deb-src http://mirrors.digitalocean.com/ubuntu/ trusty main restricted # deb http://us.archive.ubuntu.com/ubuntu/ precise main restricted # deb-src http://us.archive.ubuntu.com/ubuntu/ precise main restricted ## Major bug fix updates produced after the final release of the ## distribution. ## DigitalOcean mirrors for blazing speed! deb http://mirrors.digitalocean.com/ubuntu/ trusty-updates main restricted deb-src http://mirrors.digitalocean.com/ubuntu/ trusty-updates main restricted # deb http://us.archive.ubuntu.com/ubuntu/ precise-updates main restricted # deb-src http://us.archive.ubuntu.com/ubuntu/ precise-updates main restricted ## NB software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu ## team. Also, please note that software in universe WILL NOT receive any ## review or updates from the Ubuntu security team. ## DigitalOcean mirrors for blazing speed! deb http://mirrors.digitalocean.com/ubuntu/ trusty universe deb-src http://mirrors.digitalocean.com/ubuntu/ trusty universe deb http://mirrors.digitalocean.com/ubuntu/ trusty-updates universe deb-src http://mirrors.digitalocean.com/ubuntu/ trusty-updates universe # deb http://us.archive.ubuntu.com/ubuntu/ precise universe # deb-src http://us.archive.ubuntu.com/ubuntu/ precise universe # deb http://us.archive.ubuntu.com/ubuntu/ precise-updates universe # deb-src http://us.archive.ubuntu.com/ubuntu/ precise-updates universe ## NB software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu ## team, and may not be under a free licence. Please satisfy yourself as to ## your rights to use the software. Also, please note that software in ## multiverse WILL NOT receive any review or updates from the Ubuntu ## security team. ## DigitalOcean mirrors for blazing speed! deb http://mirrors.digitalocean.com/ubuntu/ trusty multiverse deb-src http://mirrors.digitalocean.com/ubuntu/ trusty multiverse deb http://mirrors.digitalocean.com/ubuntu/ trusty-updates multiverse deb-src http://mirrors.digitalocean.com/ubuntu/ trusty-updates multiverse # deb http://us.archive.ubuntu.com/ubuntu/ precise multiverse # deb-src http://us.archive.ubuntu.com/ubuntu/ precise multiverse # deb http://us.archive.ubuntu.com/ubuntu/ precise-updates multiverse # deb-src http://us.archive.ubuntu.com/ubuntu/ precise-updates multiverse ## NB software from this repository may not have been tested as ## extensively as that contained in the main release, although it includes ## newer versions of some applications which may provide useful features. ## Also, please note that software in backports WILL NOT receive any review ## or updates from the Ubuntu security team. ## DigitalOcean mirrors for blazing speed! deb http://mirrors.digitalocean.com/ubuntu/ trusty-backports main restricted universe multiverse deb-src http://mirrors.digitalocean.com/ubuntu/ trusty-backports main restricted universe multiverse # deb http://us.archive.ubuntu.com/ubuntu/ precise-backports main restricted universe multiverse # deb-src http://us.archive.ubuntu.com/ubuntu/ precise-backports main restricted universe multiverse ## DigitalOcean mirrors for blazing speed! deb http://mirrors.digitalocean.com/ubuntu/ trusty-security main restricted deb-src http://mirrors.digitalocean.com/ubuntu/ trusty-security main restricted deb http://mirrors.digitalocean.com/ubuntu/ trusty-security universe deb-src http://mirrors.digitalocean.com/ubuntu/ trusty-security universe deb http://mirrors.digitalocean.com/ubuntu/ trusty-security multiverse deb-src http://mirrors.digitalocean.com/ubuntu/ trusty-security multiverse # deb http://security.ubuntu.com/ubuntu precise-security main restricted # deb-src http://security.ubuntu.com/ubuntu precise-security main restricted # deb http://security.ubuntu.com/ubuntu precise-security universe # deb-src http://security.ubuntu.com/ubuntu precise-security universe # deb http://security.ubuntu.com/ubuntu precise-security multiverse # deb-src http://security.ubuntu.com/ubuntu precise-security multiverse ## Uncomment the following two lines to add software from Canonical's ## 'partner' repository. ## This software is not part of Ubuntu, but is offered by Canonical and the ## respective vendors as a service to Ubuntu users. # deb http://archive.canonical.com/ubuntu precise partner # deb-src http://archive.canonical.com/ubuntu precise partner ## Uncomment the following two lines to add software from Ubuntu's ## 'extras' repository. ## This software is not part of Ubuntu, but is offered by third-party ## developers who want to ship their latest software. # deb http://extras.ubuntu.com/ubuntu precise main # deb-src http://extras.ubuntu.com/ubuntu precise main
Ubuntu LTS版本没有得到许多更新。 实际上，你在LTS版本中看到的唯一更新是
请参阅https://wiki.ubuntu.com/StableReleaseUpdates#When什么时候LTS版本得到更新。