Cant access tty job control turned off

After migrating a Debian virtual machine from VMware ESX to XenServer, the virtual machine fails to boot.
The boot sequence fails at the following error: “ALERT! /dev/sda1 does not exist. Dropping to a shell!”
and i had this message "can't access tty job control turned off"
any ideas to help resolving the error will be appreciate
thanks*

Error:
ALERT! /dev/sda1 does not exist. Dropping to a shell!
can't access tty job control turned off
