You want to determine the size of the Active Directory database.
If you are in DS Restore Mode, you can use
ntdsutil to report the size of the Active
> ntdsutil files info
If you are not in DS Restore Mode and run this command, you will receive the following error message:
*** Error: Operation only allowed when booted in DS restore mode "set SAFEBOOT_OPTION=DSREPAIR" to override - NOT RECOMMENDED!
As you can see, it is possible to override this failure by setting
SAFEBOOT_OPTION environment variable to
DSREPAIR, but I do not recommend this unless you
know what you are doing. By setting that environment variable, the
ntdsutil command will not stop you from performing
other commands. This can be very dangerous.
Another method, which is safer and easier, is to bring up a command
shell by going to Start → Run, typing
cmd.exe, and pressing Enter. Then type
<NTDSDir> is the full path to
the ntds.dit file. Finally, run
dir command; the output will show the size of
The size of the Active Directory database on a domain controller is effectively the size of the ntds.dit file. This file can vary slightly in size between domain controllers even within the same domain due to unreplicated changes or differences with nonreplicated data.
You should monitor the size of this file on one or more domain controllers in each domain to ...