Active Directory relies on a variety of services and features to function properly. If one of these services should fail, you are sure to get unusual or erratic behavior. This chapter covers the following failure scenarios and suggests recovery options for them:
Loss of a DNS Server and its impact on clients and domain controllers
Loss of a domain controller, including the loss of a Global Catalog server and Flexible Single Master Operations (FSMO) role masters
Loss of key replication components, including bridgehead servers, Inter-Site Topology Generator (ISTG) servers, and WAN links
Loss or corruption of the Active Directory database, including methods for backing up and restoring the database contents
Performing Active Directory maintenance, including moving ESE files to alternate locations, defragmenting the AD database, and setting AD configuration parameters
By the time you finish this chapter, you'll have the basis for a set of best practices to use when planning for Active Directory recovery and for performing ongoing maintenance.