Re-installing Ubuntu while mainting dual-boot with Windows?

Question

I am kinda new to ubuntu and the whole linux field, and have some concerns.

First, I currently have Linux Mint 17 dual booting with Win8.1 via grub 2, my question is how to remove linux mint and install ubuntu instead while keeping the windows untouched.

I can go ahead and give it a shot by formatting the mint's partition but i already had enough failures this week installing mint (14 freaking hrs) so i want to do it right this time, if format the the mint and swap partitions and recreate them with bigger sizes will grub identify the change and remove the mint's entry and recognize windows?

Im installing in 1 TB HD and 300 gb left, and giving 100 gb for ubuntu divided between (/, /home, /swap) how much space to give each? considering i have 8 gb physical ram.

when making a separated home partition and happens that i want to reinstall/upgrade/change dist, will the new system recognize that /home partition from previous installation or will i have to recreate or point to it manually?

About the data/shared partition how does it works? will it benefit me if i created one? i switch between the 2 OS's alot

What i want is a stable dual booting machine that i dont have to reconfigure in the long run.

Please advice.

Answer 1

I would do a new partitioning, removing mint partition and creating your new Ubuntu partitions. At the end of the installation grub will identify your windows and your new Ubuntu and add the entries for both of them.

I would go for some 30 Gb for /, 8 Gb for swap and the remaining for /home, unless you're a developer and you want to install lots of thing in /opt, then I would use 50 Gb for /, 8 for swap and divide the remaining between /home and /opt

When you will reinstall/upgrade, you must manually indicate what every partition is used for, and it will only modify the /, nor the others

Personnally I don't like a lot the shared data partition, but if you switch between OS often it could be a good idea.