You need a separate partition for each installed Linux system. That is correct. But you don't normally need to mount one Linux system on another. You only do that for maintenance.

For example, here is (part of) my Crux fstab file:
This allows me to occasionally mount the non-Crux partitions as a user for inspection but prevents accidental modification. The noauto option prevents them from being mounted at boot. If I want to modify them, I have to mount them as root, or boot into them. I have similar lines in my other fstab files.

To use your new fstab file, simply do the following as root:
This commits you to nothing irrevocable, since you still have both files. If you can't boot into the system, boot into your other one, mount the partition and reverse the changes.

2 members found this post helpful.

Thanks Hazel, just one last question [I hope]. By the other system you mean the Live DVD?

I intend to make the plunge on Saturday because tomorrow is the annual picnic for my Meetup group and I don't want to run into computer problems just before the event as I am the organiser.

Oops! I thought you had Mint and Xubuntu. Or haven't you installed xubuntu yet?

But yes, you can always use a live disk as a rescue device to correct something like a bad fstab file.

Thank you! No, I couldn't install Xubuntu because it would tell me that /dev/sda4 was not mounted -- so I was going around in circles. I would mount /dev/sda4, but as I later discovered, only temporarily, and so when I went to install Xubuntu from a Live disk I would lose the temporary status during the reboot. That is when the saga with fstab entered the scene.

Come Saturday I will take the plunge,and if it works I intend to document my steps because I have learnt a lot, including the use of Gedit, lsblk, and handling fstab!

Hi RenH,

To be clear:

- you DO need a separate partition to install another linux distro, or at the very least, some contiguous unpartitioned space that will be used by the Xubuntu installation program to create one for you.

- in the case where you already do have a separate, empty partition created (this is your case), you DO NOT need to mount it before installing the distro.

So ... there is no need for you to modify your fstab or to try and mount /dev/sda4 manually. Again, please reread my previous rather long post (#25) ...

Hope this helps - let us know how it goes.

Thanks Rickkkk, I've read your answer [25] and understand what I have to do. I will try it on Saturday first, although I suspect this is what I did do before. If it doesn't work I will mount it manually. It's almost reached a point where I want to do a mount [permanent] just to prove to myself I can do it. However,prudence comes first.

You never mount your target partition during an install. It does in fact get mounted (on the live root system) but not by you! The installer mounts it and then copies all the files over to it. Most installer programs don't even need an existing partition and prefer not to have one. They just want some empty space that they can partition themselves.

I think you are getting confused because you already have a Linux system on that drive and you think it needs to be involved in the new installation somehow. Well, it doesn't. Forget that it exists. Leave the rest of your drive empty and let the installer do its job without you interfering.

1 members found this post helpful.

Greetings Hazel and Rickkkk. I am happy to tell you [and very happy for myself] to tell you that I followed your instructions and installed Xubuntu on a new automatically created partition -- sda3. I first unmounted sda4 before trying to install. I deleted sda4 and rejoined the two partitions and then allowed the installer to partition my one partition.

I "think" if I had not unmounted sda4 but made a permanent boot via Fstab and then used the the fourth option [to install Xubuntu in a different location] it might have worked. But what you told me was so much simpler, and what I should have done from the beginning instead of the wild goose chase I undertook.

Again, thank ye all! I now have to see if I can use the programmes I installed on Mint or install again.

I'll leave this thread open a little while longer in case you have more words of wisdom on my newly installed xubuntu and/or partition.

Hey RenH - great news - glad to hear you got xubuntu installed correctly.

Just a quick note to clarify that mounting a file system happens during an active session with an operating system, either automatically at boot (through fstab) or manually as needed by the user. Once you shut down, reboot, etc. .. everything is unmounted. It is not a permanent state. Therefore, mounting a file system while in Mint would have had absolutely no impact on an installation of a second operating system - it would have been unmounted in any case as soon as you shut down Mint.

The different operating systems installed on any given computer do not see each other - they blissfully ignore each other's existence ...

Let us know how things go and please don't hesitate to ask should you want any help with anything :-)

Cheers.

1 members found this post helpful.

Thank you Rickkk - I found your last reply very helpful as it ties it all up for me with respect to mounting. I intend to make a crib sheet for future reference, which I can also share with friends I am trying to persuade to abandon Microsoft for Linux.
The next few days I intend to play around with Xubuntu.

Don't beat yourself up for having got it wrong the first time. See what a lot you learned! That's the joy of Linux. If you make a mistake in Windows, you don't learn anything by it except not to do that again.

Yes, you are correct, and I do like the feeling of being my own "master" with Linux. Microsoft reached the absolute peak of arrogance when it prevented the user from turning off without first updating. That was the last straw. I have never regretted removing Microsoft.
My next step is to see what I have to install. Is it possible to use the programmes installed on my Mint system?

Yes, most of them will be in Xubuntu too because Mint is based on Ubuntu

I just want to thank Hazel and Rickkkk, and the others too, for the help. I finally installed all the necessary programmes in my Xubuntu partition. If VLC works and I don't have the freezing problems that I do with Mint, I may try to re-install Mint from a different source. But Xubuntu is clean and simple.

I'll mark this question as closed [if I know how to.]

You're very welcome, RenH - glad you were able to work things out the way you wanted ! Good show !

Come back anytime.

Cheers,