trying to install Ubuntu
 

Can you tell me about the error message "no root file system defined

It means that you don't have assigned a partition to be the system partition (named root-partition or /-partition), so the installer can't do his work.

If you don't have much Linux experience, you should probably just have the installer determine your partition layout for you. Just review it and makre sure it isn't doing something dumb (e.g. wiping out your Windows partition, if you're setting up a dual boot).

In the Allocate Drive Space main window, you will see your drives/partitions listed: sda, sda1, sda2, etc. or if you don't have any partition you will see free space. When you click on a partition to use or free space to create a partiton, a new window opens and you will see Mount point on the bottom left. To the right of that is a box with a down arrow. Click the down arrow and select the first option "/".

WST, from what I've observed in Linux you need three main partitions, root"\", home , and swap. go with these for now


as always if your dual booting Linux and any windows OS, Windows first

Just to clarify that: You only need one partition, the /-partition. For swap you can use a file instead of a partition and a separate /home-partition has no other reason than convenience, it is not needed.

I Know What I Said
 

Yeah, but if you happened to screw up your root partition (we all know how these things sometimes happen to the "new user"), it be nice to have those "hard to find again" files in a nice safe partition of their very own e.g /home.

You don't need a spare tire, (without saying any more on that). but it costs less than a tow truck.
I'm just saying give useful advice to a beginner and professional advice to the professional

Saving your files in a separate /home-partition is nothing more than convenient. If the disk is malfunctioning a separate /home-partition brings exactly that: nothing. If you have files that are "hard to find again" integrate them into your backup plan.

So, in short: Saying that you need three partitions for a Linux system is plain wrong and misinforming a new user. Has nothing to do with being beginner or professional.

IF HIS DRIVE WAS MALFUNCTIONING WE WOULDN'T BE HAVING THIS DISCUSSION... sure it's not needed but it's smart,your telling me having your documents on the same partition as root is safer than having them on a separate partition, isn't that one of the things Linux Gurus, such as yourself, crucify Microsoft for. Anyway WST keep your Doc files on a separate partition just to be safe as possible.(THERE, IS THAT BETTER Tobi)

(You must run backups every hour on your personal machines Tobi.) An ounce of prevention is worth a pound of cure.

You brought an error situation in this thread with a messed up root-partition. By the way, no reason to shout.

Please show me a quote where I have said that.

Nope.

Having a separate /home partition still has nothing to do with safety.

Nope, I run them when I have a reason to do it.

To make it clear: You were the one who misinformed a new user with a plain wrong statement, instead of giving reasonable advice. i just pointed that out. No reason to shout at me. If you feel offended feel free to report me to the moderators.

Sorry, forgot that's what caps meant, I'm not a snitch i don't report. hopefully your trying to teach me something.

No.. I didn't, WST did

Must have been another Guru

Say, for example, you do an upgrade that doesn't necessarily go according to plan and you have to reformat the root partition and you DO have your separate home partition, when you are done reformatting the root partition and restart your computer you will see that your desktop is just as you left it, the terminal commands that a new user might forget, are still there, etc.. It's safer to have one than not.

If you wait till you have a reason, it's probably too late

Don't you and most every other Linux user you know have a home partition? I should have said the most common, not necessary or needed, was just trying to help.

But you already knew that.