I have three disks on my computer. One HDD, two SSD's.
ON HDD - it's only free space now. In the past I had Ubuntu there.
On SSD1 - there is Windows + EFI System Partition (which -probably- is where GRUB is installed. In the past, used this partition to dual-boot the old Linux install on the HDD with the Windows one)
Now, I bought a new SSD and installed Ubuntu. Let's call it SSD2.
ON SSD2 - Ubuntu only (not specific EFI System Partition) + partition for windows files.
On the install, in the "Device for bootloader installation" option I've chosen:
"/dev/nvme0n1p4" > format: ext4
Same partition that I've installed the whole system, not a specific EFI System Partition.
So here I have two questions.
1- do I have two GRUB's installed? I mean, if I remove the SSD1, will I be able to boot into the Linux only using SSD2?
2- Is there any practical consequences to install the bootloader on the system partition (like i did on SSD2) instead of some specific EFI Partition (like I Did on SSD1)?
Did some research, and was still a bit confused, however, got some commands that can be useful to clarify my current situation to you:
sudo fdisk -l
Disk /dev/nvme0n1 (SSD2 - New): 232,91 GiB
Device Start End Sectors Size Type
/dev/nvme0n1p1 34 32767 32734 16M Microsoft reserved
/dev/nvme0n1p2 32768 253513727 253480960 120,9G Microsoft basic data
/dev/nvme0n1p4 254513152 488396799 233883648 111,5G Linux filesystem
Disk /dev/nvme1n1 (SSD1 - Old): 119,25 GiB
Device Start End Sectors Size Type
/dev/nvme1n1p1 2048 249659391 249657344 119G Microsoft basic data
/dev/nvme1n1p2 249659392 250068991 409600 200M EFI System
lsblk
sda (HDD) 8:0 0 931,5G 0 disk
└─sda6 8:6 0 7,2G 0 part
nvme0n1 (SS2 - New) 259:0 0 232,9G 0 disk
├─nvme0n1p1 259:1 0 16M 0 part
├─nvme0n1p2 259:2 0 120,9G 0 part
└─nvme0n1p4 259:3 0 111,5G 0 part /
nvme1n1 (SSD1 - OLD) 259:4 0 119,2G 0 disk
├─nvme1n1p1 259:5 0 119G 0 part
└─nvme1n1p2 259:6 0 200M 0 part /boot/efi
sudo efibootmgr -v
BootCurrent: 0000
Timeout: 0 seconds
BootOrder: 0000,0002,2001,2002,2003
Boot0000* ubuntu HD(2,GPT,giant_number)/File(\EFI\ubuntu\shimx64.efi)RC
Boot0002* Windows Boot Manager HD(2,GPT,giant_number)/File(\EFI\Microsoft\Boot\bootmgfw.efi)WINDOWS.........x...B.C.D.O.B.J.E.C.T.= (giant_number)......
Boot2001* EFI USB Device RC
Boot2002* EFI DVD/CDROM RC