What are the contents of stdout.log? Typically, if this file is growing a lot, it points to debugging being enabled.
If you have installed LMS onto the wrong drive, the best recourse is to uninstall it, and reinstall it on the desired drive. You cannot simply move files.
That said, there are few things which can be relocated to alternate drives. These are the config archive and the software image repository. Both have the potential of being rather large, but they are not the only two heavy hitters. This is why a reinstall might be best.
To move the config archive, go to RME > Admin > Config Mgmt > Archive Settings. Follow the online help on how to create the new archive directory on the alternate drive.
To move the software image repository, go to RME > Admin > Software Mgmt > View/Edit Preferences. Again, consult the online help for details.