White Space Logging is enabled to know the actual "White Space" in the domain controller database. You enable this by modifying the following registry of the domain controller.
- KEY NAME: HKLM\System\CurrentControlSet\Services\NTDS\Diagnostics\
- Entry Name: 6 Garbage Collection\
- Value: 1(enabled), 0(disabled)
After this has been enabled on a domain controller, an Event ID 1646 will be generated next time the Garbage Collection process runs. The Garbage Collection process runs every 12 hours, by default. The Event ID will tell you the actual white space on the domain controller.