Rebuilt server but won't boot after import of pool

Hi,

I had to rebuild my backup server due to the USB drive failing, and after i tried to import the existing pool it just gets stuck in a boot loop that i'm unable to get out of

Even if there was some way for me to manually delete the pool and start fresh that would be fine

Any ideas what on earth is going on here?

Couple of pics attached from my IPMI
thanks