在 Linode (Ubuntu 16.10) 上，通过启用 UFW 防火墙后
sudo ufw allow OpenSSH
sudo ufw enable
sudo ufw allow in "Apache Full"
（虽然我不完全确定防火墙设置是我的问题的根源......）
sudo apt-get updateIgn:1 http://mirrors.linode.com/ubuntu yakkety InRelease
Ign:2 http://mirrors.linode.com/ubuntu yakkety-updates InRelease
Ign:3 http://mirrors.linode.com/ubuntu yakkety-backports InRelease
Err:4 http://mirrors.linode.com/ubuntu yakkety Release
404 Not Found [IP: ****:****:*::****:**** 80]
Err:5 http://mirrors.linode.com/ubuntu yakkety-updates Release
404 Not Found [IP: ****:****:*::****:**** 80]
Err:6 http://mirrors.linode.com/ubuntu yakkety-backports Release
404 Not Found [IP: ****:****:*::****:**** 80]
Ign:7 http://security.ubuntu.com/ubuntu yakkety-security InRelease
Err:8 http://security.ubuntu.com/ubuntu yakkety-security Release
404 Not Found [IP: ****:***:****::** 80]
Reading package lists... Done
E: The repository 'http://mirrors.linode.com/ubuntu yakkety Release' does no longer have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
E: The repository 'http://mirrors.linode.com/ubuntu yakkety-updates Release' does no longer have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
E: The repository 'http://mirrors.linode.com/ubuntu yakkety-backports Release' does no longer have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
E: The repository 'http://security.ubuntu.com/ubuntu yakkety-security Release' does no longer have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
源文件
/etc/apt/source.list# deb http://mirrors.linode.com/ubuntu/ yakkety main restricted
# deb http://mirrors.linode.com/ubuntu/ yakkety-updates main restricted
# deb http://security.ubuntu.com/ubuntu yakkety-security main restricted
# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb http://mirrors.linode.com/ubuntu/ yakkety main restricted
# deb-src http://mirrors.linode.com/ubuntu/ yakkety main restricted
## Major bug fix updates produced after the final release of the
## distribution.
deb http://mirrors.linode.com/ubuntu/ yakkety-updates main restricted
# deb-src http://mirrors.linode.com/ubuntu/ yakkety-updates main restricted
## N.B. 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.
deb http://mirrors.linode.com/ubuntu/ yakkety universe
# deb-src http://mirrors.linode.com/ubuntu/ yakkety universe
deb http://mirrors.linode.com/ubuntu/ yakkety-updates universe
# deb-src http://mirrors.linode.com/ubuntu/ yakkety-updates universe
## N.B. 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.
deb http://mirrors.linode.com/ubuntu/ yakkety multiverse
# deb-src http://mirrors.linode.com/ubuntu/ yakkety multiverse
deb http://mirrors.linode.com/ubuntu/ yakkety-updates multiverse
# deb-src http://mirrors.linode.com/ubuntu/ yakkety-updates multiverse
## N.B. 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.
deb http://mirrors.linode.com/ubuntu/ yakkety-backports main restricted universe multiverse
# deb-src http://mirrors.linode.com/ubuntu/ yakkety-backports main restricted universe 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 yakkety partner
# deb-src http://archive.canonical.com/ubuntu yakkety partner
deb http://security.ubuntu.com/ubuntu yakkety-security main restricted
# deb-src http://security.ubuntu.com/ubuntu yakkety-security main restricted
deb http://security.ubuntu.com/ubuntu yakkety-security universe
# deb-src http://security.ubuntu.com/ubuntu yakkety-security universe
deb http://security.ubuntu.com/ubuntu yakkety-security multiverse
# deb-src http://security.ubuntu.com/ubuntu yakkety-security multiverse
我已经尝试了
sudo apt-get dist-update我也做过
unset http_proxyunset https_proxyapt-get -o Acquire::ForceIPv4=true update我可以
ping 8.8.8.8...还没有任何效果。有人知道如何解决这个问题吗？
Linode支持回复：
您使用的 Ubuntu 版本似乎已达到其生命周期结束状态。
https://wiki.ubuntu.com/Releases
您可以参考以下链接，看看是否可以通过其他方式更新。另一个选项是为您的服务器部署更新的 Ubuntu 映像并将数据复制到新磁盘。
我也被困在这个问题上。但我成功了。
我必须将
/etc/apt/sources.list对于我的托管公司 Linode 列出的其他更新，我使用了以下内容：
我必须将
--allow-unauthenticatedsudo apt-get update --allow-unauthenticated然后我就可以完成更新了。
这个问题已经让我抓狂好几天了，最终通过完全卸载 ufw 并清理所有剩余资源，然后使用相同的端口规则再次进行全新安装来解决它。
首先禁用ufw：
sudo ufw disable
取出包装：
sudo apt-get remove ufw
清除以前的ufw配置文件：
sudo apt-get purge ufw
删除未使用的包并清理本地存储库：
sudo apt-get autoremove
sudo apt-get clean
再次重新安装 ufw 并根据您的喜好再次设置规则：
sudo apt install ufw
我不知道是什么导致初始安装和设置失败，根本没有改变任何东西..奇怪。