Ubuntu无法更新的问题

公司的一台电脑，操作系统为Ubuntu 14.04 LTS，默认的语言为英语。

通过远程连接到终端，执行更新命令

admin@lnxServer:~$ sudo apt update[sudo] password for admin:Err http://us.archive.ubuntu.com trusty InRelease                           Err http://us.archive.ubuntu.com trusty-updates InRelease                   Err http://us.archive.ubuntu.com trusty-backports InReleaseErr http://security.ubuntu.com trusty-security InReleaseErr http://us.archive.ubuntu.com trusty Release.gpg  Could not resolve 'us.archive.ubuntu.com'Err http://us.archive.ubuntu.com trusty-updates Release.gpg  Could not resolve 'us.archive.ubuntu.com'Err http://security.ubuntu.com trusty-security Release.gpg  Could not resolve 'security.ubuntu.com'Err http://us.archive.ubuntu.com trusty-backports Release.gpg  Could not resolve 'us.archive.ubuntu.com'Reading package lists... DoneW: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/trusty/InRelease  W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/trusty-updates/InRelease  W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/trusty-backports/InRelease  W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/trusty-security/InRelease  W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/trusty/Release.gpg  Could not resolve 'us.archive.ubuntu.com'W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/trusty-updates/Release.gpg  Could not resolve 'us.archive.ubuntu.com'W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/trusty-backports/Release.gpg  Could not resolve 'us.archive.ubuntu.com'W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/trusty-security/Release.gpg  Could not resolve 'security.ubuntu.com'W: Some index files failed to download. They have been ignored, or old ones used instead.

怀疑是更新源的问题，于是更改更新源

$ sudo nano /etc/apt/sources.list

添加国内的163源，更新，依旧出错。

添加阿里云的源，更新，仍然出错。

考虑是DNS的问题。

$ sudo vi /etc/resolv.conf 

公司的DNS为210.21.196.6，保存。

执行更新

admin@lnxServer:/etc/apt$ sudo apt-get updateIgn http://us.archive.ubuntu.com trusty InRelease                          Hit http://us.archive.ubuntu.com trusty-updates InRelease                  Hit http://us.archive.ubuntu.com trusty-backports InRelease                    Hit http://us.archive.ubuntu.com trusty Release.gpg                            Hit http://us.archive.ubuntu.com trusty-updates/main Sources               Hit http://us.archive.ubuntu.com trusty-updates/restricted Sources             Hit http://us.archive.ubuntu.com trusty-updates/universe Sources               Hit http://us.archive.ubuntu.com trusty-updates/multiverse Sources             Hit http://us.archive.ubuntu.com trusty-updates/main amd64 Packages            Hit http://us.archive.ubuntu.com trusty-updates/restricted amd64 Packages      Hit http://us.archive.ubuntu.com trusty-updates/universe amd64 Packages        Hit http://us.archive.ubuntu.com trusty-updates/multiverse amd64 Packages      Hit http://us.archive.ubuntu.com trusty-updates/main i386 Packages             Hit http://us.archive.ubuntu.com trusty-updates/restricted i386 Packages       Hit http://us.archive.ubuntu.com trusty-updates/universe i386 Packages         Hit http://us.archive.ubuntu.com trusty-updates/multiverse i386 Packages       Hit http://us.archive.ubuntu.com trusty-updates/main Translation-en            Hit http://us.archive.ubuntu.com trusty-updates/multiverse Translation-en      Hit http://us.archive.ubuntu.com trusty-updates/restricted Translation-en      Hit http://us.archive.ubuntu.com trusty-updates/universe Translation-en        Hit http://us.archive.ubuntu.com trusty-backports/main Sources                 Hit http://us.archive.ubuntu.com trusty-backports/restricted Sources           Hit http://us.archive.ubuntu.com trusty-backports/universe Sources             Hit http://us.archive.ubuntu.com trusty-backports/multiverse Sources           Hit http://us.archive.ubuntu.com trusty-backports/main amd64 Packages          Hit http://us.archive.ubuntu.com trusty-backports/restricted amd64 Packages    Hit http://us.archive.ubuntu.com trusty-backports/universe amd64 Packages      Hit http://us.archive.ubuntu.com trusty-backports/multiverse amd64 Packages    Hit http://us.archive.ubuntu.com trusty-backports/main i386 Packages           Hit http://us.archive.ubuntu.com trusty-backports/restricted i386 Packages     Hit http://us.archive.ubuntu.com trusty-backports/universe i386 Packages       Hit http://us.archive.ubuntu.com trusty-backports/multiverse i386 Packages     Hit http://us.archive.ubuntu.com trusty-backports/main Translation-en          Hit http://us.archive.ubuntu.com trusty-backports/multiverse Translation-en    Hit http://us.archive.ubuntu.com trusty-backports/restricted Translation-en    Hit http://security.ubuntu.com trusty-security InRelease                       Hit http://security.ubuntu.com trusty-security/main Sources                    Hit http://us.archive.ubuntu.com trusty-backports/universe Translation-en      Hit http://security.ubuntu.com trusty-security/restricted Sources              Hit http://us.archive.ubuntu.com trusty Release                                Hit http://security.ubuntu.com trusty-security/universe Sources                Hit http://security.ubuntu.com trusty-security/multiverse Sources              Hit http://us.archive.ubuntu.com trusty/main Sources                           Hit http://security.ubuntu.com trusty-security/main amd64 Packages             Hit http://us.archive.ubuntu.com trusty/restricted Sources                     Hit http://security.ubuntu.com trusty-security/restricted amd64 Packages       Hit http://security.ubuntu.com trusty-security/universe amd64 Packages         Hit http://security.ubuntu.com trusty-security/multiverse amd64 Packages       Hit http://us.archive.ubuntu.com trusty/universe Sources                       Hit http://security.ubuntu.com trusty-security/main i386 Packages              Hit http://security.ubuntu.com trusty-security/restricted i386 Packages        Hit http://us.archive.ubuntu.com trusty/multiverse Sources                     Hit http://security.ubuntu.com trusty-security/universe i386 Packages          Hit http://security.ubuntu.com trusty-security/multiverse i386 Packages        Hit http://security.ubuntu.com trusty-security/main Translation-en             Get:1 http://security.ubuntu.com trusty-security/multiverse Translation-en [2,570 B]Hit http://security.ubuntu.com trusty-security/restricted Translation-en       Get:2 http://security.ubuntu.com trusty-security/universe Translation-en [75.8 kB]Hit http://us.archive.ubuntu.com trusty/main amd64 Packages                    Hit http://us.archive.ubuntu.com trusty/restricted amd64 Packages              Hit http://us.archive.ubuntu.com trusty/universe amd64 Packages                Hit http://us.archive.ubuntu.com trusty/multiverse amd64 Packages              Hit http://us.archive.ubuntu.com trusty/main i386 Packages                     Hit http://us.archive.ubuntu.com trusty/restricted i386 Packages               Hit http://us.archive.ubuntu.com trusty/universe i386 Packages                 Hit http://us.archive.ubuntu.com trusty/multiverse i386 Packages               Hit http://us.archive.ubuntu.com trusty/main Translation-en                    Hit http://us.archive.ubuntu.com trusty/multiverse Translation-en              Hit http://us.archive.ubuntu.com trusty/restricted Translation-en              Hit http://us.archive.ubuntu.com trusty/universe Translation-en                Ign http://us.archive.ubuntu.com trusty/main Translation-en_US                 Ign http://us.archive.ubuntu.com trusty/multiverse Translation-en_US           Ign http://us.archive.ubuntu.com trusty/restricted Translation-en_US           Ign http://us.archive.ubuntu.com trusty/universe Translation-en_US             Fetched 78.4 kB in 38s (2,053 B/s)                                             Reading package lists... Done

可以正常更新了。