(SOLVED) Unable to boot system from HDD connected to USB port

Hi guys,

I've been lurking here for years and have managed to sift out all the information I've ever needed to get my N54l OMV setup and running well, so thanks for all your passive help!

I've finally hit a stumbling block that I'm sure is a relatively easy fix: using Stoneburner, currently with 5 x 3TB discs in RAID 5 with a 256GB system disk. I want to swap the system disk for another 3TB drive in the raid, and move the system to a 2.5" HDD plugged in to the onboard USB port (via a 2.5" SATA to USB caddy). Pretty straightforward, right? Well, I've made a copy of the system disk using the Clonezilla backup plugin, and I've spent all weekend going back and forth cloning the whole disk again and again, installing OMV from scratch and cloning my system partition, repairing the boot sector with Boot Disk Repair and I just can't get the system to boot when plugged in to USB (I've tried using both the onboard and the external ports).

When trying to do so, the system attempts to boot from the USB HDD but Grub fails (can't find i386, or similar message - hence the boot repair, which reported 'successful', although the next boot attempt gave a different Grub boot error).

Anyway, the long and short is that I finally had the bright idea to test the cloned disk in one of the SATA ports, rather then USB and lo and behold it boots without a problem (without any boot repair, just a straight clone of my existing system disk - which you would expect!), so there's nothing wrong with the cloned drive.

I'm convinced there must be something I've missed in the BIOS settings (or could it be the 2.5" caddy I'm using?), and I'm hoping it's more obvious to one of you than it is to me. I know that this should work, and I would really appreciate it if somebody could point me in the right direction rather than me wasting any more time trying to figure it out!

(Once this is sorted I will resize the boot drive and move to a smaller HDD I have lying around, as I know 256GB is overkill).

A thousand thank yous in advance,
Brian

The Grub error I'm seeing is /boot/grub/i386-pc/normal.mod not found (but it must be 'there' as it's booting when plugged into sata, as above)

I've also tried swapping the drive into a different caddy and get the same result.

Could it be the drive itself? It's an Hitachi if that makes any difference?

I'm tearing what little hair I have left out!

Thanks for that. I don't think my server has usb 3 (could be wrong, I'll have to check). Will install the backports kernel tomorrow and give that a go.

Installing the backports kernel didn't resolve the issue. However, figuring I had nothing to lose, I resized the cloned, updated system disk and cloned that to a smaller capacity Seagate HDD. And it works! Not sure why the Hitachi HDD with the same image refused to boot to Grub, but I guess it doesn't really matter now. Now, to add the 6th disk to RAID. Thanks for your help, appreciated!