Description of problem:
VM status change to down when migrating.
RHEV-M event: Migration of VM migrate failed. Error: Lost connection with qemu process.

Version-Release number of selected component (if applicable):
rhev-hypervisor6-6.2-20111026.2.el6
vdsm-4.9-110.el6.x86_64
rhevm-3.0.0_0001-50.el6.x86_64
qemu-kvm-0.12.1.2-2.204.el6.x86_64
libvirt-0.9.4-20.el6.x86_64

How reproducible:
100%

Steps to Reproduce:
1. Install RHEV-H in two same model machines.
2. Register RHEV-H to RHEV-M, approve RHEV-H in same cluster.
3. Create new NFS domain and create VM.
4. VM status is "up".
5. Migrate VM.
6. VM status change to "migrating from".
7. VM status change to "down".
  
Actual results:
VM status change to down when migrating, VM can up successful by click run button.

Expected results:
VM live migration can successful.

Additional info: