Not having updated the Cluster OS since its install (why break something when it works?) I find that Windows Server 2016 is reaching the point at which an upgrade to 2019 is called for.
I KNOW Microsoft do not recommend in place upgrades for Server OS, however it does work (mentioned in at least two places in Microsoft official 'how-to' documents - one about server upgrades in general the other in the Cluster Upgrade FAQ)
I have a two node cluster, using Stawind vSAN Free.
I think that the two possible workflows are
- move all the roles to Node2,
- upgrade the server OS in-place for Node1
- move the roles back to Node1
- upgrade the server OS in-place for Node2,
- move all the roles to Node2
- evict Node1,
- clean install 2019 on node 1 (without deleting the SW Volume),
- reinstall Starwind
- restore the SW Config
- add Node1 back in to the cluster
- rinse and repeat for Node2.
In this second workflow the re-install Starwind bit is the one that is kind of concerning - not that it is difficult, just because I haven't done it and want to minimise the chances for me to roayally screw things up!
For both there are also probably a couple of re-syncs needed as well (each one takes a while - about 30 hours; yes I know, I should have a 10G interface but I don't

anyone had an experience doing this either way or got any hints/tips?
Regards
Ben