Hi
Following these instructions exactly
1
https://ubuntu-mate.community/t/gpar...dows-users/797

2
https://ubuntu-mate.community/t/inst...lse-method/651

to partition a 1TB SSD and install ubuntu-mate off a live USB.

My partition is different than the instructions and is as follows(also
see attached)

1 esp 550MiB
2 root 40 GB
3 home 640 GB
4 swap 128GB

At the blinking cursor I can either alt-F4 to bo to UEFI or esc and I
continue to boot to my 2nd SSD with a Windows 10 install.

If I try holding the shift key on reboot I instead see capital GRUB with
a blinking cursor on a black screen.

Hitting return takes me to my 2nd SSD with a Win 10 install.

The only change I have made to my UEFI is to disable FastBoot.

Next I tried Boot Repair from a live USB, and attempted to reinstall my grub, but for some reason it did not 'see' my ESP at sda1, only sda and sda2 which is my root partition.

So, probably a mistake, I let it go ahead and install grub in sda2.

After rebooting, same result, blinking cursor.

Next I relaunched gparted from a live USB and reexamined my partitions.

Now I was seeing an error icon on my ESP at sda1, saying it wasn't recognized because I was missing certain files (see attached esp_warning)

I am also getting a warning whenever launching gParted about a discrepancy between Linux and the driver descriptor in regards to physical block size. (attached LibParted_warning)

I realize this is a long post but trying to include as much information as possible.

Thanks for any feedback!


Question> For my GPT partitioned drive, does it matter what partition
flag I have set for my ESP ?
It was set to 'boot', then I tried 'bios-grub' but neither worked


Results of boot-repair here
http://paste.ubuntu.com/23750353/

The Boot Repair results DO seem to indicate a few things wrong.
I assume that reinstalling grub with Boot repair AFTER setting my ESP flag to bios-grub may be part of the reason

And before anyone comments on my swap size
1- storage is relatively cheap.
2- I use my Linux PC primarily for particle simulations in Houdini and got some feedback from Linux-Houdini experts a lot more knowledgeable than I
3- If after several months of use I discover I rarely use that amount, I assume I can easily increase my home partition and reduce swap.

Attached Thumbnails

     

You do not need swap anywhere near that large. 4GB is plenty of swap. The system will never make use of that large swap size.

Once again, the system will not make use of that large amount of swap space. In this case more is not better.

You can only have one esp per disk so if you attempted to install to /dev/sda and/or /dev/sda1 and/or /dev/sda2, that may have caused you some issues.
I would boot from a live usb and chroot into the installation then reinstall grub since boot-repair doesn't seem to be effective