Sometimes P2V migrations fail in SCVMM after the 70% completion phase. This is usually post copy/post virtualization fixup. This could also be a situation where it seems the job is hanging at 70% in the VMM console.  Another symptom that might be noticed would be that the P2V job has completed w/ Info. Often you will see this error:

Warning (13210)

Timeout occurred while waiting for VM integration services to be installed on virtual machine <name> residing on host <host>

Recommended Action

Ensure that the version of the VM integration services binaries matches the version of the guest operating system in the virtual machine and then try again.

The issue can be confirmed by starting the VM in Hyper-V. This will show it crashing upon bootup with a STOP 0x7B error. This may occur if certain registry entries that are added by 3rd-party storage providers or physical hardware providers when these were installed are not removed because the software was not uninstalled prior to P2V process, the software was installed but these settings were not removed prior to P2V, or these were not removed during the P2V fixup phase. These registry entries are preventing your computer from starting correctly.

When this happens, you can do one of two things. Prior to P2V on the source machine search your registries for "UpperFilters" and "LowerFilters." You can usually track down culprits of post P2V STOP 0x7B's this way.

For example, you may find the following:

HKLM\SYSTEM\CurrentControlSet\Control\Class\{71A27CDD-812A-11D0-BEC7-08002BE2092F}

UpperFilters = snapman timounter

Or

HKLM\SYSTEM\CurrentControlSet\Control\CriticalDeviceDatabase\gendisk

LowerFilters = ZetSFD

Simplay removing these values prior to running a P2V, will resolve the issue although this could be time consuming. You could also mount the VHD in another OS (such as Windows 7 or Windows Server 2008 R2) and load the hives. Then you can search and make the same changes. Bear in mind, you will need to make sure the right ControlSet hive is actually modified (check HKEY_LOCAL_MACHINE\SYSTEM\Select first) or modify all ControlSets.