SQL Server FCI won't start after OS Upgrade I have a two node sql server 2008 r2 cluster that we just did an OS upgrade from windows 2008 r2 to windows 2012 r2, the OS upgrade was done in place so the SQL Server Installation stayed in tack.  The cluster role won't come back online saying it's couldn't find any IP address that this instance depends on.  

Everything comes on line except SQL Server resource and looking in the sql server log file it shows that error sql server is starting up as I can see master and model get started up.

From the sql log:


  Could not find any IP address that this SQL Server instance depends upon.  Make sure that the cluster service is running, that the dependency relationship between SQL Server and Network Name resources is correct, and that the IP addresses on which this SQL Server instance depends are available.  Error code: 0x5.


Are there additional steps that need to be taken with Windows Server 2012 r2 that need to be done to get SQL Server 2008 r2 to be able to run in a failover cluster?
Prior to Windows Server 2012 R2, doing an in-place upgrade of Windows for an FCI is not supported. Per Microsoft's documentation: 


  Upgrading the Windows operating system of a failover cluster is not
  supported for operating systems before Windows Server 2012 R2. To
  upgrade a cluster node running on Windows Server 2012 R2, see 
  Cluster Operating System Rolling Upgrade.


Because your starting OS was Windows Server 2008 R2, you are unable to do an in-place upgrade to Windows Server 2012 R2. Instead, you will need to build a new Windows Cluster, do a fresh SQL install for a new FCI, then migrate to that new FCI.

You can do this using existing hardware by removing a node from the cluster, doing the fresh install of both Windows &amp; SQL, then repeating the process one node at a time to move servers from the old cluster to the new cluster.

Once you are upgraded to Windows Server 2012 R2, you will be able to do in-place OS upgrades in the future.

Given that you've already upgraded the OS, your best bet is going to be to uninstall SQL Server, and re-install the FCI from scratch.