Ubuntu 16.04 LTS Release

"Ubuntu 16.04 lts release" Ubuntu 16.04 LTS Release date has been formally identified as April 21, 2016, codenamed Xenial Xerus.
Ubuntu16.04 will be the 6th long-term support version of Ubuntu, the most popular open source operating system, and its first LTS version was released in June 2006.
Ubuntu 16.04 xenial Xerus will contain Unity 7 desktop, Linux Kernel 4.4, and hyper-multi-app updates
ZFS file system supported by default, snap package and Deb
Ubuntu Software Center was canceled: The GNOME software was replaced.
As a new long-term support version, Ubuntu 16.04 will receive 5 years of BUG fixes and critical security patch updates.

A great system, since the first contact with Linux began to use, every April 21, October 21, the development of new versions, never skip tickets;

Ubuntu 16.04 lts Update source is ready to use, the majority of domestic mirrors have been synchronized;

1. Quickly change your Ubuntu source and update to 16.04 Lts method (with 15.04 conversion to 16.04 LTS For example, other versions of similar, directly replace the corresponding release code is good):

sudo sed-i "s/vivid/xenial/g"/etc/apt/sources.listsudo apt-get update && sudo apt-get
     Dist-upgrade

2, can also be used in simple and safe way:

First refresh the source and then execute

sudo apt-get  updatesudo update-manager-c-D

3, can directly modify the source:

First back up the source, then modify, delete all the contents of the previous, paste into the following 16.04 Lts source can:

Deb http://mirrors.hust.edu.cn/ubuntu/xenial main restricted universe multiverseDeb http://mirrors.hust.edu.cn/ubuntu/xenial-security main restricted universe multiverseDeb http://mirrors.hust.edu.cn/ubuntu/xenial-updates main restricted universe multiverseDeb http://mirrors.hust.edu.cn/ubuntu/xenial-proposed main restricted universe multiverseDeb http://mirrors.hust.edu.cn/ubuntu/xenial-backports main restricted universe multiverseDEB-SRC http://mirrors.hust.edu.cn/ubuntu/xenial main restricted universe multiverseDEB-SRC http://mirrors.hust.edu.cn/ubuntu/xenial-security main restricted universe multiverseDEB-SRC http://mirrors.hust.edu.cn/ubuntu/xenial-updates main restricted universe multiverseDEB-SRC http://mirrors.hust.edu.cn/ubuntu/xenial-proposed main restricted universe multiverseDEB-SRC http://mirrors.hust.edu.cn/ubuntu/xenial-backports main restricted universe multiverse

PS: Use the official source, please use Method 1, 2, before using, the first to change your Ubuntu source to official, the steps are: Click on the left side of the Software Center, click menu, click Edit, Software source, then pop out the dialog box to select Ubuntu official, determined after the update source.
Novice recommends using the second method, this method is painless and safe.

Ubuntu 16.04 LTS Release