I have an internal SSD containing a single partition with Ubuntu on it. I am currently booting from this partition. However, to actually boot a second (HDD) drive is required which has an EFI partition on it. I want to remove the HDD and continue to boot Ubuntu from its location on the SSD, without having to reinstall anything.
I am thinking what I need to do is to resize the partition on the SSD to allow space for an EFI partition, move it (the start of the existing partition ahead/up), create an EFI partition before it, and then install something on the new EFI partition so it will boot from the existing Ubuntu install on what would now be the second partition. I have bits and pieces of what I think I need to do (for instance, I think GParted can do the moving and resizing) but I don't have a clear enough picture of exactly what I need to do in order to avoid risking data loss. Also, it seems like this is an uncommon procedure, as I see these various activities mentioned as parts of other processes, but never creating an EFI partition from scratch.
Exactly what steps do I need to do to safely modify my single partition SSD to boot by itself?
sudo update-grub
those entries not gone?? – PRATAP Dec 17 '18 at 12:18