I am new to Ubuntu and I have just finished installing 13.10 amd64 on my PC. This will replace my Windows 7 as my only OS.

I just want to clarify some issues that've been bugging me. I tried reading posts with the same topics but I just can't wrap my head to it yet.

I partitioned my 80GB drive into:

• /root: 30GB (sorry for the confusion, I actually meant /)
• /home: 40GB
• /var : 3GB
• swap : 4GB (2GB of mem)

Please correct me if I'm wrong about these:

• All of the users' documents are saved in their respective folders in /home. But say I want to clean install (format) Ubuntu, I don't need to make backups of /home and /var as they are on separate partitions. But when re-installing, do I just choose /root and format and it will recognize all the partitions (not making another /home and /var inside /root)?

• Downloaded packages (from all the repositories) and all their dependencies are saved in /var. So after re-installing on the same PC (assuming I'm offline), it will just use the latest updates in /var if I choose to update? And if all the installed apps and their dependents are all in there, all I need to do is re-install them without encountering errors? I have also read that you can back them up using aptoncd and then adding the DVD to the sources. So if I download all the high ranking apps using Synaptic, could I then have an all-in-one DVD installer?

• 30GB for / is excessive because the bulk of files will either be in /home (personal, downloads, music, videos) or /var (updates, packages, installed apps)?

Please excuse me for asking such a question but I really want to explore and learn more.