KFM
KFM feature will have no effect if your folders are already redirected using Group Policy. KFM is useful pretty much only for small businesses or companies without much local IT stuff.
Migration
As for migration, it might be complex or simple depending on your environment, number of users and volume of data you would like to move to OneDrive.
In short, the project plan might looks like this:
- Contact Microsoft FastTrack to help you with the project. They can either do the migration themselves, or just help you create migration plan to follow yourself. The service is free. They can also provide you with the tools and documentation you might need later
- Analyze user files you want to move and identify any possible issues, e.g. unsupported characters, path lengths, etc. There are several commercial tools available on the market, including free tool from Microsoft.
- Investigate analysis results and mitigate possible issues.
- Prepare for migration by creating necessary GPOs, Security Groups, etc.
You can find a lot of helpful information about OneDrive GPO here. https://support.office.com/en-us/article/use-group-policy-to-control-onedrive-sync-client-settings-0ecb2cf5-8882-42b3-a6e9-be6bda30899c
- At maintenance hours, migrate your user files, remove files them from network server, apply new GPO setting and deal if any issues you might still have.
NOTE: if you simply assign your users new GPO and redirect network files to local disk, then OS itself would move files to new location. After logon local file could be synced to OneDrive.
While this approach needs no user interaction it has two issues:
- file move would happen during user's logon. This means users would be unable to use their PC. So while it works for users who has several MBs of data, it is not a goood idea if your users has GBs/TBs
- if anything would happen to PC/disk during sync to OneDrive, files might be lost since they are already gone from server
There are a lot of other steps you might want to do, like communicating to your users what is changing, ask them to delete unused files to make migration faster, etc.
There are also some issues after you migrate because of the old paths to network files are saved in registry and configuration files. So testing any business software you use is a must (but that goes without saying).
To sum up, the project might be really complex or really quick. It totally depends on your environment. But if you are alreayd using Group Policy and network shares KFM will not be much of a help for you.