This assumes you are willing to part with your data; fresh install means wiping previous data.
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- Select the desired drive for Scratch, and then 'add GPT partition'
- <leave blank intentionally to fill remaining space on this drive>; ext4; <use dropdown to select /Other>, and then name it 'scr'>
Create
Expand title Example of setting up Scratch drive 
Step 4d - Setup the
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Data drive
Easy again, since we're using the entire capacity of this last drive. In this case, I am using the only drive that can be selected now since I have already configured the others.
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If all steps above were performed correctly, it will NOT complain about nouveau being loaded, ignore all questions until it asks to install or configure nvidia-xconfig for you, say no at this prompt. If it fails to install, it will clearly say that the NVIDIA Driver installation has failed. If this occurs, try running the installation file again, and provide us the LAST screen before the NVIDIA driver installation fails so we can further investigate.
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