P2V Windows 2008 R2 in DSRM, work with domain member but not with DC

Hi,
I could successful do a P2V migration of a Windows 2008 R2 domain member server in DSRM safe mode. But when I try the same procedure with
the domain controller, I got that VSS snapshot error that says that VSS can not run in DSRM.

FAILED: Unable to create a VSS snapshot of the source volume(s).

Error code: 2147754758 (0x80042306)

So, my question is, why the VSS snapshot worked in the win2k domain member(no roles)?

Can I migrate the domain controller in offline mode with another tool? Or is there any way to migrate that domain controller using vmware converter in DSRM mode?

Thanks

Oliver