installationpackage-managementpartitioningupgrade
I keep experimenting with my Ubuntu so I have to reinstall it sometimes.
I just wanted to know whether I can create another partition only for my installed application(from software center) so that I can modify my system but have the application folders (I guess /var/cache/apt and /usr/bin) be safe and I can again use the applications after a reinstall or upgrade?
NOTE: I already have a different partition for my /home folder.
When reinstalling on a system having only Ubuntu installed we have four options from the installer:
As soon as the partitioner gparted opens it's window we are able to inspect the exiting partitions on our drive to select which ones to use for the new installation.
By default all used partitions are marked as "do not use the partition". After having selected a partition we may press "Change..." to edit this. The following window lets us define how to use the selected partition:
/home for your HOME partitiondo not tick "format" to prevent from formatting (and deleting) your existing data
\, \swap or any other partitions you want to reuse.only tick format on those partitions you really want to delete
In case we had installed without choosing the mount point of our existing HOME we will create a new /home/ directory filled with default values for the newly created user.
If we then need to reuse the old HOME partition we have to make sure to mount it on boot. The steps are similar to how I outlined in my answer to the following question but without the copying bits:
Basically, you need to edit your /etc/fstab to mount the existing partition as /home. You also should delete (or better rename to be able to undo) the newly created empty /home of your new installation before you can use the previous HOME partition on the next reboot.
To avoid doing this when a user is logged in it is better to perform the above from a live session.
The advantage of keeping your old HOME partition is that all your data and all your application setting will be preserved.
But this also may be disadvantageous in case your broken installation came from bad user settings. These of course will then also be restored.
Best Answer
It does not work like that in Ubuntu (and in Linux in general).
Unlike Windows, Ubuntu does not keep all the files needed for an application in a single folders. Rather it shares common files needed by the system as well as other apps. So, files are stored in folders for different types of common files/libraries.
The default installation of Ubuntu contains a fair share of applications, such as LibreOffice. These will get reinstalled / upgraded in the default location.
As a result, the additional apps (those installed afterwards) probably will get into dependency issues if you put them in a different partition, as there will be two sets of
/usr/binetc. and the files won't be in sync. So, if you use the set in the root (/) partition the system and the default applications will work but the applications in the other partition may not, and if you try to use (mount) the ones in the other partition, the system and the default applications will break as they will try to use the older libraries.See Backing up third party apps before reinstalling Ubuntu for alternate means of saving application lists and re-install in one go.
Hope this helps