You can move the AD database (ntdis.dit) to another drive by using the Directory Services Restore Mode (DSRM).
- Reboot the DC
- Press F8 and choose "Directory Services Restore"
- Enter the DSRM password when prompted
- Open a command prompt and type the following (eg. to move the database to the D: drive):
NTDSUTIL
files
move db to d:\NTDS
q
q
- Now reboot the DC in normal operation mode.
