User profile configuration is taking advantage of the User Profile Disk (UPD) technology in Windows Server remote desktop services. It's a new technology that makes the profile management a lot easier.
Each user is assigned a virtual hard disk that is holding their profiles, including their home folders (Documents, Downloads, Favorites, Desktop, Appdata, etc.).
Profile data size
The maximum size of the disk is 100 GB. The size is a standard we chose so it can give users enough space for all their files and ost/pst files but also give them certain limit so they don’t overuse the storage space. The user profile disk will grow as the user downloads files and saves more data in it.
The total storage of the drive that hosts user profiles will need to be increased as the user profile disks take up more space.
The user profile disk limit can be increased if needed. If not increased, it's thin provisioned so it will not allow to exceed the allocated 100 GB size. There is a tool that can help in identifying who the user profile disks belong to and it's called Sidder.
Moving Data to user’s drive
You can move data to user's drive through group policies or by mounting the drives and copying the files you need into the user profile disk when logged in as admin in the file server.
User profile data location
User profile disks are located on the file server, under C:\Profile folder or D:\Profile folder for newer deployments.
If multiple session host servers are created, the profile is still hosted on the file server and is roaming to the user session.
The profile folder is created for users when their account is created in the cloud Active Directory.
User’s drive security
User Profile Disk is permanently housed in the file server and will only load for the owner. Anything stored in any of the profile folders will be safe for the user and there's no need to create individual folders for each user.
User Profile Disks and admin accounts
The UPD is configured for a collection, meaning that it's configured as a computer policy for the servers which are part of that collection, in other words, when it comes to UPD's the same setup applies for a standard user and an admin.
UPD can only be mounted to 1 session at a time. If you have multiple servers in a collection then you can only log into 1 of the user session servers at a time, if you log into multiple collection servers at the same time, only the first session which was able to successfully mount the UPD will be able to use the actual profile, all other sessions will be logged in with a temporary profile.