HP Microserver Gen8 and ZFS Grub Problems

Hi,

i installed a Raid1 Mirror with ZFS with Proxmox 3.4 ISO.
I surely rebooted 5 times without Problems.
Now I am always booting to Grub Rescue Console and I have no Idea why.

At the Moment I moved the Disks to a N54L, the previous Model.
And they are working fine.

Any Ideas and help?

Chriz