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AD corruption - Urgent

pmckenna11 asked
Just on my way to check out a down server (SBS 2008). We have lost Exchange and it appears there is some corruption in AD. There was some kind of power failure and the server did not shut down gracefully.

I will probably need to restore AD and Exchange. I do have SBS backup from last night before the corruption but don't see a way to do an AD restore through the backup GUI. I also have flat file backups of all the drives and directories.

Server is up but no one can connect to exchange either through Outook or OWA. There are error messages relating to AD corruption in the logs.

Any advice on how to approach this? In particular what would be the best way to approach the AD recovery. Again I can log into the server

Here are a couple of relevant log snippets:

MSExchangeIS (2772) First Storage Group: The log range read from the file "C:\Program Files\Microsoft\Exchange Server\Mailbox\First Storage Group\E00.log" at offset 852480 (0x00000000000d0200) for 53248 (0x0000d000) bytes failed verification due to a range checksum mismatch.  

MSExchangeIS (2772) First Storage Group: Corruption was detected during soft recovery in logfile C:\Program Files\Microsoft\Exchange Server\Mailbox\First Storage Group\E00.log.

Active Directory Certificate Services did not start: Unable to initialize the database connection for XXX-SVR-SBS2008-CA.  The database is damaged. 0xc8000226 (ESE: -550).
Watch Question

Check the events related to AD.
Do you have any other DC?


It is SBS with only the single server

The Active Directory Certificate Services service terminated with service-specific error 3355443750 (0xC8000226).

Also the AD certificate service is set to auto but is not running and will not start. Not sure if it should be running by default or not
Top Expert 2012

Run a dcdiag post results
Senior Technical Lead
If you sure that the AD is corrupted then you need to reboot the server and start it as Directory service restore mode and restore the system state from previous working backup.

Before than that couple of suggestions,

1) Have you tried Last Known Good Configuration?
2) Have you rebooted the server again and check whether it's working properly.
3) Is all the services started related to AD,DNS, IIS etc?

If you got certificate service error then your AD is alright.
Run dcdiag/netdiag and check.


Just arrived on site. I still need to run dcdiag/netdiag but it actually looks like the only issue is Exchange. Everyone can log in and connect to server shares and services without issue. I am assuming that an Exchange restore from backup will take care of the problem.

I am currently doing local Outook exports for each of the users just to be safe before trying a restore. I have not used the SBS2008 exchange restore function before. I assume all I need to do is select the restore Exchange box and let it go. Anything else I should be aware of before trying to restore the Exchange datastore from backup?