Ubuntu 11.10升级到12.04

1. 前言

现在的最新版本已经是13.04了，不过一则12.04是所谓的LTS，二来系统是用来做最终演示的，还是保守一点好。另外相信升级的过程都是一样的

2. 步骤

Linux 升级异常简单：一个button或一条命令就够了。之前在GUI里，点一下“升级”按钮就行了。现在只能远程ssh到远端机器，用console更自然一些（虽然也可以调出software center之类的）

升级命令： do-release-upgrade

3. 过程

3.1 问题

不出问题就不叫linux了:)

An unresolvable problem occurred while calculating the upgrade: E:Unable to correct problems, you have held broken packages. This can be caused by:
* Upgrading to a pre-release version of Ubuntu
* Running the current pre-release version of Ubuntu
* Unofficial software packages not provided by Ubuntu"

基本上，应该是已有的11.10版本out of date，和新的（在那之后更新过的）11.10版本有了冲突。这可以从日志/var/log/dist-upgrade/apt.log中看到，有很多held back的packages. 如果做apt-get -u upgrade，对应的有很多kept back 的cases.

3.2 Solution

sudo apt-get update 
sudo apt-get dist-upgrade
sudo apt-get --purge autoremove
sudo apt-get autoclean
sudo apt-get purge $(dpkg -l | awk '/^rc/ { print $2 }')

from http://askubuntu.com/questions/202730/how-to-fix-the-unable-to-calculate-upgrade-issue-when-upgrading-from-12-04-to

另外同样的问题：Upgrade to 12.04 Failed due to held back packages

注：尽管都提到要先删除ppa packages (e.g. using ppa-purge or from SoftwareCenter)，我没有删也没有问题－－－可能本来就从来没装过

4. 其他

4.1 log files

The following logs are related to apt upgrades:

/var/log/apt/history.log /var/log/apt/term.log /var/log/dpkg.log

For dist-upgrade, it's

/var/log/dist-upgrade/[apt.log | main.log]

4.2 Advanced Packaging Tools (APT)

这个题目足够单独成章甚至系列了。只列几个链接

APT HOWTO (Obsolete Documentation)  虽说“过期了”但我发现还是很有用。大量详尽的例子把很多用法解释的很清楚。至少入门是很好的

DebianPackageManagement - Debian Wiki

 AptGet/Howto

基本上，目前理解的层次结构是：dpkg-deb---> dpkg--->[Apt | apt-get | aptitude CLI mode] ---> [Synaptic | adept | aptitude console mode (ncurses)]

4.3 Other tips

Run Synaptic from command line

Do NOT run GUI apps with sudo. Instead run:
gksudo synaptic

Sudo doesn't setup the environment correctly for GUI apps. The equivelant in KDE is kdesudo

How to keep processes running after ending ssh session?

Use GNU Screen (not maintained anymore), ormore advancedtmux