14.04 install and don't want to format partitions

[jjgrego1103]

I have a dual-disk system, one has windows installed, the other ubuntu 13.10. I'd like to upgrade to 14.04, but don't want to have to
wipe out a couple partitions I have (/opt and /home). During the install, is there some option that will allow this to happen? I don't mind if
the rest of the disk is reformatted, I just don't want to have to reinstall everything I've configured.

Thanks,

John

[ubfan1]

First backup anything important on the disk -- things can go terribly wrong, from a disk failure, power glitch, or even just a wrong selection of an option. Now, you said upgrade, and 13.10 to 14.04 is straightforward. Your partitioning will be kept, nothing is formatted (and I don't even know of such an option to actually request any formatting during an upgrade).
Now configurations should be kept for the new versions of applications, but expect to do some tweaking, new features are generally added, of which old configurations know nothing. Some programs like Postgresql when upgraded may actually keep the old version running, and install the new one with new defaults (like the 5433 port instead of 5432). That is to allow some testing of the database before you decide to switch over, but the source header files will still have the 5432 port as a default, so you will have to manually sort things out yourself if you are using programs like ecpg. Of course, anything you installed directly instead of from the Software Center you will need to take care of yourself.
Upgrades are better than full install in that respect, but after a few, you do find a lot of cruft has built up, which a full install cleans out.

[oldfred]

If doing a new install not an upgrade then you have to use Something Else. That is the only install option that lets you have more than the default of / & swap with grub2's boot loader installed to sda.
You want more than default partitions and grub installed to sdb.

But either way you upgrade or install good backups are vital. Export list of installed apps, and backup /home, /etc and any additional edits or programs you have installed that may be in /, so you could restore if you have to do a new install.

If upgrading be sure to turn off any proprietary drivers, like video or Internet. And remove any PPAs. These cause major issues as install often cannot find something non-standard and then install stops half way thru leaving system unbootable.

Lots of detail, screenshots and essential info.14.04 Something Else example
http://www.dedoimedo.com/computers/ubuntu-14-04-install-guide.html
http://askubuntu.com/questions/343268/how-to-use-manual-partitioning-during-installation
http://askubuntu.com/questions/163962/install-alongside-option-missing-how-do-i-install-ubuntu-beside-windows-using

Any install with Something Else which is required with external drives or any second drive or any install with separate /home
Also shows combo box with location of grub2 boot loader
https://help.ubuntu.com/community/Grub2/Installing
Does not hightlight changing boot loader to sdb, if external drive, but shows other install screenshots:
http://askubuntu.com/questions/312782/how-to-install-ubuntu-on-separate-hard-drive-in-a-dual-boot
http://askubuntu.com/questions/274371/install-on-second-hard-drive-with-startup-boot-optiond