Warning: There areÂ two commands mentioned in this how to, both that require double dashes – - but for some reason WordPress is not rendering that correctly. After each dpkg hit space and hit the dash button twice. Sorry for the the inconvenience.
A clean install or an upgrade? That’s a question that keeps tossed around every new Ubuntu release. Common wisdom would suggest that a clean install would probably be better, however the inconvenience of losing current installed apps and configuration makes most of us shy away from this path. But what if I told you that you could have the good of both worlds? A fresh install and keeping your apps and configuration intact?
Keeping your configuration intact is pretty straight forward and obvious. Just backup your /home folder onto an external drive or whatever. Make sure you also grab the hidden files, don’t do my mistake!
Now for the current applications. Basically we just need to make a full list of the installed apps.
sudo dpkg --get-selections > /home/user/package.selections
Of course don’t forget to backup package.selections on the external hard-drive. Also you should backup your /etc/apt/sources.list file since you probably have some extra sources listed over there. Now you can go about your business and do a fresh install.
Once your done with the fresh install, copy the file package.selections into your home. Then copy your sources.list file into /etc/apt/ and update it to match your current distro (e.g Gutsy –> Intrepid) you can use CTRL + H in gedit for that. Then do a “sudo apt-get update” ,and finally invoke:
sudo dpkg --set-selections /home/package.selections && apt-get dselect-upgrade
apt-get will now start downloading all your apps, this will take some time depending on the number of apps you have installed.
Once that’s done, just copy your backup-ed /home over the current /home (again don’t forget hidden folders).
Log out and log back in to your shiny new fresh install!
Edit: As the commentators below also mentioned, it would also be wise to have your /home in a seperate partition (thanks Boo Radley), backÂ up /etc (thanks Bartek), and use the tar command to back up home (it will preserve your structure and permissions)