I'm trying to install Linux Mint 22.3 Cinnamon on a 256 GB SATA SSD connected through a 2.5-inch SATA-to-USB adapter. Windows is installed on a separate 512 GB Samsung NVMe drive in my ThinkPad T570, and I want to leave that internal drive untouched.
The installation completes successfully, but the external SSD will not boot. During the first installation, GRUB opened to a prompt, although I could manually start Mint with commands pointing to the external drive's second GPT partition and its /boot/grub directory. I later discovered that the installer had placed or used the EFI files on the internal NVMe. I corrected fstab, reinstalled GRUB, and created new EFI entries, but the system then began rebooting with a "Reset System" message.
I wiped the external SSD and performed another clean installation while hiding the internal NVMe from the live environment, leaving the installer access only to the external SSD and USB installer. Despite that, choosing the external SSD from the F12 boot menu still displays "Reset System," reboots, and eventually returns to Windows.
Secure Boot is disabled, USB is first in the boot order, and the external drive appears as /dev/sda in the live session. The system is an i7-7600U ThinkPad T570. Could the SATA-to-USB adapter, insufficient USB power, the SSD, or Lenovo's UEFI firmware be preventing the drive from booting? Would physically removing the internal NVMe make a difference compared with hiding it during installation?
3 Answers
Updating the ThinkPad’s UEFI/BIOS would be worth trying first, especially since external-drive boot behavior can depend on firmware bugs or compatibility fixes. Confirm that USB or the external drive is first in the boot order, then test again. The adapter or SSD could also be involved, and some 2.5-inch drives may draw more power than one USB port reliably provides.
Physically disconnecting the internal NVMe during installation can sometimes produce a different result from merely hiding it in the live environment. It prevents the firmware or installer from placing boot files on the Windows drive and makes the external SSD the only possible system disk. If the SSD still fails to boot when the NVMe is physically removed, that points more toward the adapter, USB power, the SSD, or UEFI compatibility.
Check how the firmware identifies the external disk and whether the EFI partition and GRUB installation are actually on that disk. In a live session, verify the drive and partitions with a disk-listing tool. The first attempt seeing the disk as hd0,gpt2 may not match every later boot, although the current “Reset System” message suggests the firmware is failing before it reaches a GRUB prompt.
The live session reports the external SSD as /dev/sda. The first installation could boot manually from GRUB, but after the clean reinstall the firmware immediately shows “Reset System” and reboots, so I never reach a GRUB prompt.
The external drive is already first in the boot order, and I also tried reinstalling with the internal NVMe hidden. I haven’t updated the UEFI or physically removed the NVMe yet, so those are the next things I’ll investigate.