# Flexible Single Master Operations (FSMO)

#### Flexible Single Master Operations (FSMO)

- Certain roles / jobs that can't have multiple writeable copies (conflicts)
- Every D.C has a read only copy of all roles, for recovery
- Seizing converts a read only copy of one of the above roles to a writeable copy
- 5 FSMOs 
    - Forest level (these will generally live in the root) 
        - Domain Naming Master - Config. Partition of AD - Trust Relationships, Unique Domain Names
        - Schema Master - Master copy of schema database (must be registered)
    - Domain Level (read only copy lives on every D.C.) - can be recovered via transfer and seizing 
        - RID Master - Ensures unique identifiers for every object in domain
        - Infrastructure master - allocates groups/resources across different domains
        - PDC Emulator Master - Passwords, time, GPO replication across domains

[![image.png](https://note.human-bean.net/uploads/images/gallery/2026-07/scaled-1680-/3Gyimage.png)](https://note.human-bean.net/uploads/images/gallery/2026-07/3Gyimage.png)