This post is just a friendly reminder to myself and everyone who get tricked by an environment that has been upgraded from the initial release of Dynamics AX2012, namely RTM, with or without Feature Pack, to either Release 2 or any of the consecutive releases. What trick am I referring to? I am thinking about the fact that unless you've removed the old Modelstore, you now have two different Modelstores for each environment.
You will have the upgraded Modelstore in the separate Modelstore Database, but you will also have the old Modelstore inside the Business Database. It does not do anything, except occupy space. Well, there is one more annoying thing it does to me. I find myself going back and forth between RTM to R2 environments and sometimes I forget to use the correct Database name when running PowerShell commands. Imagine installing a new model to a R2 environment, only to later discover that you installed it into the idle RTM Modelstore inside the Business Database and not to the Modelstore Database. It doesn't happen ALL the time, but I've done it more than once.
So in the interest of clarity, here is a drawing explaining where the Modelstores are located. Left hand side is the previous version where everything was in one database. On the right hand side you have the new setup with two databases. And for upgraded environments, you may or may not have that remnant Modelstore sitting inside the Business Database.
The experienced AXers may argue that if you use the Config parameter when operating the Modelstore through PowerShell you will always work against the Modelstore Database, but since I often run these commands from other servers than the AOS Server I mostly use the Server and Database parameter for all operations. :-)