Windows Server® 2012 Unleashed

Moving Operation Master Roles

AD DS uses a multimaster replication model, in which any one server can take over directory functionality, and each full DC contains a read/write copy of directory objects (with the exception of RODCs, which hold, as their name suggests, a read-only copy). There are, however, a few key exceptions to this, in which certain forestwide and domainwide functionality must be held by a single DC in the forest and in each domain respectively. These exceptions are known as Operation Master (OM) roles, also known as Flexible Single Master Operations (FSMO) roles. There are five OM roles, as shown in Table 16.1.

Table 16.1. FSMO Roles and Their Scope

If the server or servers that hold the OM roles are not directly upgraded ...