Fantastic solution Slickymaster!
Originally Posted by slickymaster
I must admit I've never done this. I usually keep a list of my packages, and skim over it when setting up a clean install.
Only thing I'd add is to make a backup of your systems list of repositories. If you've added third party repositories, it's really helpful to remember what they were in case you can't find it after a reinstall.
Note that unlike Slickymaster's guide, after installing the latest system, you would not want to replace the existing sources.list file with this one. Just use it as a guide.
sudo cp /etc/apt/sources.list ~/Documents/sources.list.txt
For example, mine begins:
(note '#' means the line will be ignored by the system)
# deb cdrom:[Ubuntu 12.04.4 LTS _Precise Pangolin_ - Release i386 (20140204)]/ precise main restricted
# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb http://gb.archive.ubuntu.com/ubuntu/ precise main restricted
deb-src http://gb.archive.ubuntu.com/ubuntu/ precise main restricted
## Major bug fix updates produced after the final release of the
deb http://gb.archive.ubuntu.com/ubuntu/ precise-updates main restricted
deb-src http://gb.archive.ubuntu.com/ubuntu/ precise-updates main restricted
As you can see my sources list shows quite clearly that I am currently on my LTS install, 12.04 precise pangolin. notice how the first few repos I've included all have 'precise' in them? if you got rid of your 14.04 sources.list, and pasted this in, then Ubuntu would keep looking for updates and new software in the old repos (in the case of updates it would just keep reporting you have the latest software)
The third party repos you may have added for extra software are listed at the bottom of the list. Here are couple of mine from my 11.10 install:
Again notice how one entry is specific to the relase (saucy) and the other (spotify) uses one repository for all currently supported releases? it's the second type you'd want to use.
## This software is not part of Ubuntu, but is offered by third-party
## developers who want to ship their latest software.
deb http://extras.ubuntu.com/ubuntu saucy main
deb-src http://extras.ubuntu.com/ubuntu saucy main
deb http://repository.spotify.com stable non-free
deb-src http://repository.spotify.com stable non-free
Finally there are PPAs (personal package archives) that you may have added (I've added over thirty!) They are not in your sources list, but are also sources for your system. They live in /etc/apt/sources.d/
My first two entries are:
Now these are a folder of documents, not a nice list of instructions in one file. This answer on ask ubuntu is far too awesome for me to take credit on! You do have to also check what changes from one release to the next. For example the simply fantastic ninja ide I've been using for python programming for a little while Is now in the main repos in 14.04!
Hope its been helpful
All the best,