For the record, yes, I had to turn off checksumming on all the domU to get them to be able to transfer files reliably between themselves. I did not have to turn off checksumming on dom0 for this.
But, having said this, it doesn't really help me. With checksumming off, other things stop working as they should (MogileFS in my personal case) so I'm still not left with a viable resolution.
@janevert
For the record, yes, I had to turn off checksumming on all the domU to get them to be able to transfer files reliably between themselves. I did not have to turn off checksumming on dom0 for this.
But, having said this, it doesn't really help me. With checksumming off, other things stop working as they should (MogileFS in my personal case) so I'm still not left with a viable resolution.
But, thanks much for trying to help out. :)