I currently have a Groupwise 2014 R2 system on a SLES 11 SP4 virtual machine. I have Mobility on a separate SLES 11 SP4 virtual machine. I'm planning to upgrade to GW 2018 and SLES 12. What's the preferred way to do this?

1) Upgrade inside existing VM?

2) Build brand new SLES 12 VM and then copy over postoffice and domain data and build GW2018 from scratch?