I wanted to install a single boot Ubuntu 20.10 on fakeRAID-0 UEFI GPT by a live bootable flash disk. The system did not boot after installation, so I checked whether Ubiquity correctly installed UEFI and GRUB on the boot partition, and it verified OK.
I have found a magic workaround for my problem, I booted by a windows 8.1 DVD but did not let it to do any changes to my system and I shutdown just when the very first installation window appeared. Then I detached the DVD drive. Restarted the system and Ubuntu boots nicely.
Another observation I have is, whenever I want to use GParted in Ubuntu it complains as:
and I should hit Ignore. Otherwise if I hit Fix, the error will disappear but system will not boot next time. However if I redo the magic workaround again, everything goes well and the GParted error comes back. And I mention again that I do not need Ubuntu bootable flash at all. Also it worth mentioning I have used this magic workaround successfully from Ubuntu 14.04 till now.
My question is that what magic is done by windows DVD and how can I mimic the process within OS itself or live Ubuntu so that I get rid of windows DVD?
