我错过了将当前的 Ubuntu 15.10 升级到最新版本的机会。如果我没猜错的话，现在生命已经结束了。现在如何升级到最新版本？
请在下面查看我的系统的确切状态：
ravi@ravi-Aspire-5315:~$ ubuntu-support-status
Support status summary of 'ravi-Aspire-5315':
You have 1909 packages (91.7%) supported until July 2016 (9m)
You have 16 packages (0.8%) supported until April 2017 (9m)
You have 0 packages (0.0%) that can not/no-longer be downloaded
You have 156 packages (7.5%) that are unsupported
Run with --show-unsupported, --show-supported or --show-all to see more details
ravi@ravi-Aspire-5315:~$
此外，我已经很长时间没有更新我的系统了，软件更新程序显示需要下载 339 MB 作为安全更新和其他更新。
编辑#1
我跟着关联正如我的问题的评论中所提供的。第一次我运行以下命令更改archive.ubuntu.com为old-releases.ubuntu.com
sudo sed -i -re 's/([a-z]{2}\.)?archive.ubuntu.com|security.ubuntu.com/old-releases.ubuntu.com/g' /etc/apt/sources.list
但是当我尝试更新时，出现以下错误404 Not Found
ravi@ravi-Aspire-5315:~$ sudo apt-get update
Ign http://old-releases.ubuntu.com wily InRelease
Hit http://archive.canonical.com wily InRelease
Ign http://old-releases.ubuntu.com wily-updates InRelease
Ign http://old-releases.ubuntu.com wily-backports InRelease
Ign http://old-releases.ubuntu.com wily-security InRelease
Ign http://old-releases.ubuntu.com wily Release.gpg
Hit http://archive.canonical.com wily/partner Sources
Ign http://old-releases.ubuntu.com wily-updates Release.gpg
Hit http://archive.canonical.com wily/partner i386 Packages
Ign http://old-releases.ubuntu.com wily-backports Release.gpg
Hit http://archive.canonical.com wily/partner Translation-en
Ign http://old-releases.ubuntu.com wily-security Release.gpg
Ign http://old-releases.ubuntu.com wily Release
Ign http://old-releases.ubuntu.com wily-updates Release
Ign http://old-releases.ubuntu.com wily-backports Release
Ign http://old-releases.ubuntu.com wily-security Release
Err http://old-releases.ubuntu.com wily/main Sources
404 Not Found [IP: 91.189.88.17 80]
Err http://old-releases.ubuntu.com wily/restricted Sources
404 Not Found [IP: 91.189.88.17 80]
Err http://old-releases.ubuntu.com wily/universe Sources
404 Not Found [IP: 91.189.88.17 80]
Err http://old-releases.ubuntu.com wily/multiverse Sources
404 Not Found [IP: 91.189.88.17 80]
Err http://old-releases.ubuntu.com wily/main i386 Packages
404 Not Found [IP: 91.189.88.17 80]
Err http://old-releases.ubuntu.com wily/restricted i386 Packages
404 Not Found [IP: 91.189.88.17 80]
Err http://old-releases.ubuntu.com wily/universe i386 Packages
404 Not Found [IP: 91.189.88.17 80]
Err http://old-releases.ubuntu.com wily/multiverse i386 Packages
404 Not Found [IP: 91.189.88.17 80]
Ign http://old-releases.ubuntu.com wily/main Translation-en_IN
Ign http://old-releases.ubuntu.com wily/main Translation-en
Ign http://old-releases.ubuntu.com wily/multiverse Translation-en_IN
Ign http://old-releases.ubuntu.com wily/multiverse Translation-en
Ign http://old-releases.ubuntu.com wily/restricted Translation-en_IN
Ign http://old-releases.ubuntu.com wily/restricted Translation-en
Ign http://old-releases.ubuntu.com wily/universe Translation-en_IN
Ign http://old-releases.ubuntu.com wily/universe Translation-en
Err http://old-releases.ubuntu.com wily-updates/main Sources
404 Not Found [IP: 91.189.88.17 80]
Err http://old-releases.ubuntu.com wily-updates/restricted Sources
404 Not Found [IP: 91.189.88.17 80]
Err http://old-releases.ubuntu.com wily-updates/universe Sources
404 Not Found [IP: 91.189.88.17 80]
Err http://old-releases.ubuntu.com wily-updates/multiverse Sources
404 Not Found [IP: 91.189.88.17 80]
Err http://old-releases.ubuntu.com wily-updates/main i386 Packages
404 Not Found [IP: 91.189.88.17 80]
Err http://old-releases.ubuntu.com wily-updates/restricted i386 Packages
404 Not Found [IP: 91.189.88.17 80]
Err http://old-releases.ubuntu.com wily-updates/universe i386 Packages
404 Not Found [IP: 91.189.88.17 80]
Err http://old-releases.ubuntu.com wily-updates/multiverse i386 Packages
404 Not Found [IP: 91.189.88.17 80]
Ign http://old-releases.ubuntu.com wily-updates/main Translation-en_IN
Ign http://old-releases.ubuntu.com wily-updates/main Translation-en
Ign http://old-releases.ubuntu.com wily-updates/multiverse Translation-en_IN
Ign http://old-releases.ubuntu.com wily-updates/multiverse Translation-en
Ign http://old-releases.ubuntu.com wily-updates/restricted Translation-en_IN
Ign http://old-releases.ubuntu.com wily-updates/restricted Translation-en
Ign http://old-releases.ubuntu.com wily-updates/universe Translation-en_IN
Ign http://old-releases.ubuntu.com wily-updates/universe Translation-en
Err http://old-releases.ubuntu.com wily-backports/main Sources
404 Not Found [IP: 91.189.88.17 80]
Err http://old-releases.ubuntu.com wily-backports/restricted Sources
404 Not Found [IP: 91.189.88.17 80]
Err http://old-releases.ubuntu.com wily-backports/universe Sources
404 Not Found [IP: 91.189.88.17 80]
Err http://old-releases.ubuntu.com wily-backports/multiverse Sources
404 Not Found [IP: 91.189.88.17 80]
Err http://old-releases.ubuntu.com wily-backports/main i386 Packages
404 Not Found [IP: 91.189.88.17 80]
Err http://old-releases.ubuntu.com wily-backports/restricted i386 Packages
404 Not Found [IP: 91.189.88.17 80]
Err http://old-releases.ubuntu.com wily-backports/universe i386 Packages
404 Not Found [IP: 91.189.88.17 80]
Err http://old-releases.ubuntu.com wily-backports/multiverse i386 Packages
404 Not Found [IP: 91.189.88.17 80]
Ign http://old-releases.ubuntu.com wily-backports/main Translation-en_IN
Ign http://old-releases.ubuntu.com wily-backports/main Translation-en
Ign http://old-releases.ubuntu.com wily-backports/multiverse Translation-en_IN
Ign http://old-releases.ubuntu.com wily-backports/multiverse Translation-en
Ign http://old-releases.ubuntu.com wily-backports/restricted Translation-en_IN
Ign http://old-releases.ubuntu.com wily-backports/restricted Translation-en
Ign http://old-releases.ubuntu.com wily-backports/universe Translation-en_IN
Ign http://old-releases.ubuntu.com wily-backports/universe Translation-en
Err http://old-releases.ubuntu.com wily-security/main Sources
404 Not Found [IP: 91.189.88.17 80]
Err http://old-releases.ubuntu.com wily-security/restricted Sources
404 Not Found [IP: 91.189.88.17 80]
Err http://old-releases.ubuntu.com wily-security/universe Sources
404 Not Found [IP: 91.189.88.17 80]
Err http://old-releases.ubuntu.com wily-security/multiverse Sources
404 Not Found [IP: 91.189.88.17 80]
Err http://old-releases.ubuntu.com wily-security/main i386 Packages
404 Not Found [IP: 91.189.88.17 80]
Err http://old-releases.ubuntu.com wily-security/restricted i386 Packages
404 Not Found [IP: 91.189.88.17 80]
Err http://old-releases.ubuntu.com wily-security/universe i386 Packages
404 Not Found [IP: 91.189.88.17 80]
Err http://old-releases.ubuntu.com wily-security/multiverse i386 Packages
404 Not Found [IP: 91.189.88.17 80]
Ign http://old-releases.ubuntu.com wily-security/main Translation-en_IN
Ign http://old-releases.ubuntu.com wily-security/main Translation-en
Ign http://old-releases.ubuntu.com wily-security/multiverse Translation-en_IN
Ign http://old-releases.ubuntu.com wily-security/multiverse Translation-en
Ign http://old-releases.ubuntu.com wily-security/restricted Translation-en_IN
Ign http://old-releases.ubuntu.com wily-security/restricted Translation-en
Ign http://old-releases.ubuntu.com wily-security/universe Translation-en_IN
Ign http://old-releases.ubuntu.com wily-security/universe Translation-en
W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/wily/main/source/Sources 404 Not Found [IP: 91.189.88.17 80]
W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/wily/restricted/source/Sources 404 Not Found [IP: 91.189.88.17 80]
W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/wily/universe/source/Sources 404 Not Found [IP: 91.189.88.17 80]
W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/wily/multiverse/source/Sources 404 Not Found [IP: 91.189.88.17 80]
W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/wily/main/binary-i386/Packages 404 Not Found [IP: 91.189.88.17 80]
W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/wily/restricted/binary-i386/Packages 404 Not Found [IP: 91.189.88.17 80]
W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/wily/universe/binary-i386/Packages 404 Not Found [IP: 91.189.88.17 80]
W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/wily/multiverse/binary-i386/Packages 404 Not Found [IP: 91.189.88.17 80]
W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/wily-updates/main/source/Sources 404 Not Found [IP: 91.189.88.17 80]
W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/wily-updates/restricted/source/Sources 404 Not Found [IP: 91.189.88.17 80]
W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/wily-updates/universe/source/Sources 404 Not Found [IP: 91.189.88.17 80]
W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/wily-updates/multiverse/source/Sources 404 Not Found [IP: 91.189.88.17 80]
W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/wily-updates/main/binary-i386/Packages 404 Not Found [IP: 91.189.88.17 80]
W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/wily-updates/restricted/binary-i386/Packages 404 Not Found [IP: 91.189.88.17 80]
W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/wily-updates/universe/binary-i386/Packages 404 Not Found [IP: 91.189.88.17 80]
W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/wily-updates/multiverse/binary-i386/Packages 404 Not Found [IP: 91.189.88.17 80]
W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/wily-backports/main/source/Sources 404 Not Found [IP: 91.189.88.17 80]
W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/wily-backports/restricted/source/Sources 404 Not Found [IP: 91.189.88.17 80]
W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/wily-backports/universe/source/Sources 404 Not Found [IP: 91.189.88.17 80]
W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/wily-backports/multiverse/source/Sources 404 Not Found [IP: 91.189.88.17 80]
W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/wily-backports/main/binary-i386/Packages 404 Not Found [IP: 91.189.88.17 80]
W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/wily-backports/restricted/binary-i386/Packages 404 Not Found [IP: 91.189.88.17 80]
W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/wily-backports/universe/binary-i386/Packages 404 Not Found [IP: 91.189.88.17 80]
W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/wily-backports/multiverse/binary-i386/Packages 404 Not Found [IP: 91.189.88.17 80]
W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/wily-security/main/source/Sources 404 Not Found [IP: 91.189.88.17 80]
W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/wily-security/restricted/source/Sources 404 Not Found [IP: 91.189.88.17 80]
W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/wily-security/universe/source/Sources 404 Not Found [IP: 91.189.88.17 80]
W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/wily-security/multiverse/source/Sources 404 Not Found [IP: 91.189.88.17 80]
W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/wily-security/main/binary-i386/Packages 404 Not Found [IP: 91.189.88.17 80]
W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/wily-security/restricted/binary-i386/Packages 404 Not Found [IP: 91.189.88.17 80]
W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/wily-security/universe/binary-i386/Packages 404 Not Found [IP: 91.189.88.17 80]
W: Failed to fetch http://old-releases.ubuntu.com/ubuntu/dists/wily-security/multiverse/binary-i386/Packages 404 Not Found [IP: 91.189.88.17 80]
E: Some index files failed to download. They have been ignored, or old ones used instead.
ravi@ravi-Aspire-5315:~$
答案1
跟着文档中给出的说明：
- 打开系统设置中的“软件和更新”设置。
- 选择名为“更新”的第三个选项卡。
- 将“通知我新的 Ubuntu 版本”下拉菜单设置为“对于任何新版本”。
- 按Alt+F2并在命令框中输入“update-manager”（不带引号）。
- 软件更新程序应该打开并告诉您：新发行版“16.04 LTS”可用。
- 单击升级并按照屏幕上的说明进行操作。