Proper way to keep service enabled when updated from sysv to systemd?


I packaged xe-guest-utilities with a systemd service for Fedora.

But there is an upstream rpm package that include the same service as
a sysv one. And the
service is enabled with the 'Default-Start' info in the init script
after '/sbin/chkconfig --del xe-linux-distribution'.

And when people update the package from upstream one to the Fedora
one. Since the service changed to a systemd one. The service is then
disabled by default without regard to the sysv service.

That surprises end users. So the new package should make it compatible
in the scriptlets.
But which is the proper way?

Best Regards