The following key needs to be in one or more of your published images.
That key, if it exists in the image before a user logs in, will cause Ulayer.exe to ignore the User Layer share assignments set in the ELM, and instead have all users on this machine use the specified share for User Layer VHDs. That’s the share name only. The “Users” subtree is appended to this key to locate the actual layers.
You can deliver this in the Platform Layer or an App Layer, or as a machine GPO, as long as the registry setting is in the image before any user logs in.
Normally, when a user account logs in, the process looks like this:
- Read the main file share from the registry
- Read JSON files on the main file share to determine alternate share location, and which ones this user is assigned to
- Read JSON files on the main file share to determine elastically assigned app layers
- Create or attach the User Layer disk from User-Layer-Share-PathDOMAIN_usernameOSLayerID_OSLayerName
- Attach elastic layers
With UserLayerSharePath, step 2 is replaced by “set User Share location to the contents of the UserLayerSharePath registry key.” All Storage Location assignments for this user are ignored. All user layer VHD files will be created on the same, single share location. Publishing an image with a layer where this key is set, or setting the key after publishing with a machine GPO, will cause this specific image to behave differently from all other images based on this OS layer.