So, the inital question is simple: Have you ever successfully installed Update Manager 6.0x using PowerShell?
I'm attempting to automate a VUM install using vRA/vRO, and the easiest way to do this is to use a powershell script.
However, when we attempt an unattended install using a powershell script (www.vtagion.com...stallation-vum/) to setup VUM 6 under Windows 2012R2 / SQL Server 2012, we get an error and the installation fails.
[Error 25085.Setup failed to register VMware vCenter Update Manager extension]
Of course, the error does ot meet the crieteria set forth in the only KB we found related to the error message (KB1036055) - It seems that the error is a symptom, but not caused by the issue related in KB1036055.
The command we're building in power shell uses this format:
$Command = "/V" /qr /L*v C:\temp\vmvci.log WARNING_LEVEL=0 VMUM_DATA_DIR="$VUM_DATA_DIR" VCI_DB_SERVER_TYPE=Custom VCI_FORMAT_DB=1 DB_DSN=$DSN DB_USERNAME=$DatabaseUser DB_PASSWORD=$DatabasePass VC_SERVER_IP=$vCenterFDQN VC_SERVER_PORT=$port VC_SERVER_ADMIN_USER=$vCenterAdmin VC_SERVER_ADMIN_PASSWORD=$vCenterAdmin_Pass""
Note: The whole thing is escaped for powershell, and the Data Dir especially because it can have spaces.
The only difference is if you want to make a pre-answered install, you remove the /qr. Then you get all of the options in manual install for VUM pre-populated, and the installing person clicks Next a bunch of times. (It's actually pretty neat in a 1990s kinda way. 
)
The install logs shows us this (the server name has been removed):
MSI (s) (DC:80) [TimeStamp]: Executing op: ActionStart(Name=VM_RegisterExtension,Description=Registering Update Manager extension with the VMware vCenter Server ( FDNQ of vCenter:80),)
Action [Time]: VM_RegisterExtension. Registering Update Manager extension with VMware vCenter Server (vCenter FQDN:80)
MSI (s) (DC:80) [TimeStamp]: Executing op: CustomActionSchedule(Action=VM_RegisterExtension,ActionType=11265,Source=BinaryData,Target=*******,CustomActionData=*******)
MSI (s) (DC:78) [TimeStamp]: Invoking remote custom action. DLL: C:\WINDOWS\Installer\MSI4740.tmp, Entrypoint: VMRegisterExtension
Error 25085.Setup failed to register VMware vSphere Update Manager extension to VMware vCenter Server: (FQDN to vCenter Server).
MSI (s) (DC!14) [TimeStamp]: Product: VMware vSphere Update Manager -- Error 25085.Setup failed to register VMware vSphere Update Manager extension to VMware vCenter SErver: (FQDN to vCenter Server).
If we run the install semi-manually, that is we remove /qr from the $Command above and click next alot, the install works without issue. (...but it's not unattended / automated)
Thoughts?