With the need for python3.6 support for vdsm, and considering the best practices for Python packaging, https://fedoraproject.org/wiki/Packaging:Python#Byte_compiling we must create separated packages for python-vdsm: python2-vdsm and python3-vdsm. Having a package for python3.6 includes porting code to stop using dependencies that are python2-only or porting them ourselves if not possible some examples needed to be checked: python-subprocess32, ioprocess(https://bugzilla.redhat.com/show_bug.cgi?id=1257554), python-pthreading, sanlock-python,
This seems to me like a breaking backward compatibility change, which we don't want to do in 4.3. AFAIK in 4.3 we are only going to do code changes for parts which are broken in Python 3 but without altering Python 2 compatibility. And running VDSM on Python 3 without any issues is completely out of scope in 4.3. So moving to 4.4
VDSM is packaged for python3