i'm new to ubuntu so I don't know anything about how to allocate space for partitions and was wondering if anyone could me give some advice.

I initially wanted to avoid using windows but ubuntu doesn't scale programs very well with my lenovo yoga 2 pro 3200 x 1800 high dpi resolution so I settled on installing both.

it's 256gb ssd and after installing windows 10 I have 100gb of unallocated space left for ubuntu. now before anyone says to google it I have but with how old the information is and how different the information varies I didn't know if I should follow it.

Also I cannot select installing along side windows 10 there is no option for that my partition table was messed up so i had to use fixparts to allow ubuntu to recognise my windows 10 partition.

any advice is greatly appreciated, please and thank you.


When Ubuntu asks about how you want to partition it, select "Something else". These screenshots show Debian Jessie and Ubuntu MATE, but it shouldn't matter much.

1: The situation.

The way the partitions are arranged so far

We have the first section reserved for the first operating system, and the rest for Ubuntu (pretend that swap space isn't there).

Reproducing your problem:

That happened

This is what you mentioned before in the comments. It means that you haven't chosen what partition to install to. This is not a tutorial step; it's just in here as an explanation.

  1. To fix it:

If Windows made an empty partition, it will be something like this:

Not the first place I'd look for Add or Remove

It will have to be deleted and re-created smaller to leave room for the swap partition. Leave at least as much space as you have RAM, but more than double your RAM won't help much. If it's free space already, just skip deleting it (because it isn't there).

Deleting the partition doesn't need a screenshot

Add a partition with the little + button, set your size, select Ext4 and set it to be mounted at /.

If you've noticed inconsistencies in some of the screenshots, it's because I used different VMs.

Add another partition that fills the rest of the space and Use as swap.

That looks right to me

That should do it. Check what it's going to do; it shouldn't need to format the first partition but will for the ones you just made.

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  • thanks a lot, especially for the step by step with pictures. it must've taken awhile. – andrew Aug 10 '15 at 7:28

When you install Ubuntu, it will look at your available drives and give you options based on what it detects. If you have free space, it will offer to install to the free space. It will also offer to install alongside Windows, which IIRC defaults to half of the space to each if it can (reconfigurable, of course). You can also set up partitions manually, but Linux partitioning is different enough from Windows partitioning that I would suggest you avoid it until you know a bit more.

Edit: if your partition table is messed up, you need to make a new one, which for you means wiping the entire drive. Then install Windows using whatever space you want (bearing in mind that Windows can't read your Ubuntu partition), then Ubuntu should detect and offer to be installed in the space you left.

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  • I see but from what I understand it looks like I need to partition what space I have left into several smaller parts which consist of a /swap /root /home and ect. I'm not sure how much I should divide the unallocated space to each one. Also it won't allow me to just select the 100gb of unallocated space to install to, I receive a No root file system is defined. Please correct this from the partitioning menu. error EDIT* I understand now you're suggesting I reinstall win10 and it should fix my PT allowing for the installing along side option to show. okay, thank you. – andrew Aug 10 '15 at 3:51
  • Oh yes. My apologies. You must have a root partition; a swap partition is the normal way to go (though you can have a swap file); a separate /home partition is up to you. I thought the Ubuntu installer would work all that out for you though. – Stephen Angelico Aug 10 '15 at 3:54
  • yes from what I understand if I had been able to use the install alongside windows option it would but I ran into some problems where partitioning table wasn't detecting my windows partition so I had to use fixparts to remedy the situation, which worked but left me with the task of manually deciding how to much I should allocate to each partition. – andrew Aug 10 '15 at 3:56
  • Okay, I'll fire up a virtual machine and make sure I know how this all works. I'll also see about providing screenshots. – Stephen Angelico Aug 10 '15 at 3:58
  • New answer coming right up, just ignore this one. – Stephen Angelico Aug 10 '15 at 4:30

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