When patching a DAG cluster you can run the Microsoft script StartDagServerMaintenance.ps1 from
C:\Program Files\Microsoft\Exchange Server\V14\scripts
This script basically moves the cluster resources of itself, pauses the replication and a few other tasks. However if you run the script from a non-elevated Powershell window you will get the error :-
Call-ClusterEXE: cluster.exe did not succeed, but 5 was not a retry-able error code. Not attempting any other servers. This may be an expected error by the caller. Log-Error : Start-DagServerMaintenance: Failed to suspend the server SERVERNAME from hosting the Primary Active Manager, Returned 5.
Close the Exchange PowerShell Window and Launch a new elevated one. The command will now run. However if your running a 2 node DAG then you will need to do it manually. I will be covering how to do this in a later post.