The AD data base is store in c:\windows\ntds\NTDS.DIT.

The SYSVOL folder stores the server's copy of the domain's public files. The contents such as group policy, users etc of the SYSVOL folder are replicated to all domain controllers in the domain.

Five roles are there in FSMO:

Schema Master(Forest Wide)
• Domain Naming Master (forest-wide)
• PDC Emulator (domain-wide)
• RID Master (domain-wide)
• Infrastructure Master (domain-wide)

The Schema Master role owner is the domain controller that is allowed to make updates to the schema. No other server can process changes to the schema. If you attempt to update the schema on a DC that doesn’t hold the Schema FSMO, the DC will return a referral to the schema master role holder. The default schema master role owner is the first server to be promoted to a domain controller in the forest.

The Domain Naming Master role owner is the server that controls changes to the forest-wide namespace. This server adds and removes domains and is required to rename or move domains within a forest, as well as to authorize creation of application partitions and the addition or removal of their replicas. Like the Schema Master, this role owner defaults to the first DC you promote in a forest.