What steps does the Recovery Manager Forest Edition agent perform on the DC?
The Forest Edition agent is required on each DC to manage the steps that need to be initiated locally, including rebooting the system into DSRM (Directory Services Restore Mode), restoring the DC from backup and rebooting it back into regular mode.
Specifically, the Forest Edition agent performs the following steps:
1. Reboots the DC into DSRM mode
2. Restores the AD database on the DC from backup
3. Quarantines the DC so it cannot replicate
Isolation or quarantining is an important part of the forest recovery procedure. During the restore Forest Edition disables replication with DCs that are not reachable or not included in the recovery project so that they will be unable to communicate with the corrupt DCs once they come back on the network with their restored copy of AD.
First of all, the Forest Edition agent disables all inbound and outbound replication of the Active Directory. This is done in DSRM mode, just after restoring the DC from the backup.
When a DC is in DSRM mode the Active Directory is offline, and therefore no replication happens. Disabling the replication in the DSRM mode guaranties that no replication will take place even after rebooting the DC into the normal mode.
4. Reboots the DC into normal mode
5. Isolates the DC from other DCs
The next step towards the isolation is resetting the passwords. On each recovered DC we reset:
At this stage the recovered DCs are isolated from the corrupt DCs. The only thing left is to reboot the DC to make sure all new passwords were applied.
6. Third and final reboot of the DC
The FR agent reboots the DC into the normal mode again and enables the Active Directory replication.
***This solution only applies to the Forest Edition of Recovery Manager for AD***