This browser is no longer supported.
Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support.
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(0, 45%, 10%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EYN%3C/text%3E%3C/svg%3E)
Hi,
We are in the process of migrating our windows server 2012 servers to 2019 and we are using failover cluster to maintain our SQL always on.
As we know , it's only possible to get to 2019 through windows 2016 for compatibility reasons and i'm familiar with the in-place upgrade (https://learn.microsoft.com/en-us/windows-server/failover-clustering/upgrade-option-same-hardware) but i have a new 2016 server on new hardware which i want to add to my cluster.
According to this article (https://learn.microsoft.com/en-us/windows-server/failover-clustering/cluster-operating-system-rolling-upgrade) I learn that "When the first Windows Server 2016 node joins the cluster, the cluster enters "Mixed-OS" mode, and the cluster core resources are moved to the Windows Server 2016 node" .
This actually is what causing the issue for me since once I add the first 2016 server to the cluster it transfers control to it while it's not configured yet and this causes my cluster to go offline.
Does someone knows if there is a way to avoid this transition or to mitigate it somehow? I don't like the idea of a guided failure ( that is offline cluster until the new 2016 node is properly configured).
I would appreciate any help you can offer me.
Thanks,
Yishai
Not sure I understand right, but after you upgrade from Windows Server 2012 R2 to Windows Server 2016, then add the 2016 server to the cluster.
Hi @CosmogHong-MSFT and thank you for your reply.
In my case i'm using a new server with windows 2016 and not an upgraded 2012 server.
it's possible that in-place upgrade from 2012 to 2016 won't affect the cluster in the same way since it's already configured but that's not our use case
And what I am confused is why you need a new server with windows 2016 instead of using Cluster OS Rolling Upgrade.
That would be because i want to keep my 2012 server for rollback and not destroy it by wiping my system drive and installing another windows version on it
edit.
I ended up editing the cluster IP of the evicted server to the IP of the new server before adding it to the cluster and that minimized the time the cluster is offline