It is important to keep in mind that we are dealing strictly with FRS and not Distributed File System (DFS). FRS is the engine that moves data among replica set members , which can be part of SYSVOL or DFS. DFS can be used without using replication or by using a different replication engine. Whereas SYSVOL only exists on domain controllers (DCs), DFS replica sets can be present on DCs or member servers. Some of these terms apply to DFS as well. Note that FRS and DFS are covered in Chapter 5.
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burflag : A Registry value named for "backup and restore flags." This value is set to D4 on the source domain controller (DC) in an authoritative restore operation, and D2 on the satellite DCs. In a nonauthoritative restore operation, it is set to D2 on the source and the target DC. It is a Dword value located at HkeyLocalMachine\System\CurrentControlSet\Services\Ntfrs\Parameters\backup\restore\Process at startup .
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change order : The way File Replication Service (FRS) communicates with partners to notify them of changes to the replica set.
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inbound log : Keeps track of incoming changes.
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inbound replica partners : Set of replica members that provides data to a given replica member for a given replica tree. These servers are also referred to as upstream partners.
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junction point : Also referred to as a reparse point, directory junction, and volume mount point, a junction point is a physical location on a hard disk that points to another location on a disk or storage device.
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morphed directory : A directory that has been replicated, but is in conflict with another that has the same name . These duplicate directories or files are renamed by prefixing the name with NTFRS_xxxxxxxx where xxxxxxxx is a random eight-digit number.
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NTFRS jet database : NTFRS uses a jet database to record transactions, located in %SystemRoot%\ntfrs\jet\ntfrs.jdb . It produces several logs that are useful in troubleshooting:
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outbound log : The set of change orders generated for a given replica tree. The changes could originate locally or come from an inbound replica partner. These change orders are eventually sent to all outbound replica partners. The outbound log is a table in the File Replication Service (FRS) database.
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outbound replica partners : Set of replica members to which a given replica member provides data for a given replica tree. Also referred to as downstream partners.
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replica set : In File Replication Service (FRS), two or more computers configured to replicate the contents of a file folder. The individual computers are referred to as replica members.
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replica partner (or member) : The immediate upstream and downstream partners of a given replica member are referred to as its replication partners. Upstream partners are also referred to as inbound partners. Downstream partners are referred to as outbound partners.
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staging directory : A directory for temporary files being replicated by File Replication Service (FRS). When a change is made to a file, a copy of the changed file is copied , compressed, and made available to downstream partners.
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SYSVOL tree : Directory of files and folders that is replicated by File Replication Service (FRS) on domain controllers (DCs) in the FRS replica set. This usually consists of Group Policy templates, associated files, and logon scripts.
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USN journal : NTFS feature that identifies changes made to a file in the NTFS. File operations (create, delete, modify, and so on) are assigned a USN number for tracking.
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version vector : A vector of Volume Sequence Numbers (VSNs) representing NTFRS changes containing the originating Global Unique Identifier (GUID) and associated VSN of each change. The version vector is used to tell whether the replica member is up-to-date with the replica tree, and to filter updates sent from its inbound partners, to ensure that updates are not reapplied.
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version vector join (vvjoin) : When a domain controller (DC) joins the domain, a vvjoin is performed with each inbound partner to obtain all the updates. A full vvjoin is performed for a new DC. A partial vvjoin is performed between DCs to keep each other up to date, and only replicates changes. This is performed on File Replication Service (FRS) and Distributed File System (DFS) replicas.
