23 V

value: A data element associated with a key.

vendor ID payload: A particular type of ISAKMP payload that contains a vendor-defined constant. The constant is used by vendors to identify and recognize remote instances of their implementations. This mechanism allows a vendor to experiment with new features while maintaining backward compatibility. For more information, see [RFC2408] section 3.16.

version chain vector: A data structure that maps machine GUIDs to sets of version sequence numbers.

version sequence number (VSN): A 64-bit unsigned number. Version sequence numbers are assigned to global version sequence numbers as part of file metadata in monotonic increasing order.

version vector: (1) A mapping from machine identifiers to version sequence numbers. The Distributed File System Replication (DFS-R) Protocol uses a generalization of version vectors called version chain vectors.

(2) A vector of volume sequence numbers (VSNs), with one entry per replica set member, as identified by originator GUID. All change orders carry the originator GUID of the originating member and the associated VSN. As each replica member receives the update, it tracks the VSN in a vector slot that is assigned to the originating member. This vector specifies whether the replica tree is current with each member. The version vector is then used to filter updates from inbound partners that may have already been applied. The version vector is also delivered to the inbound partner when the two members join. When a new connection is created, the version vector is used to scan the file ID table for more recent updates that are not seen by the new outbound partner.

version vector join (vvjoin): The process in which a downstream partner joins with an upstream partner for the first time. It is also called initial sync.

virtual cluster number (VCN): The cluster number relative to the beginning of the file, directory, or stream within a file.

virtual connection: A Server Message Block (SMB) connection between an SMB client and SMB server.

Virtual Disk Service (VDS): The service component running on the server.

Virtual Disk Service (VDS) object: An instance of a class that exposes one or more DCOM interfaces to query or configure the Virtual Disk Service, the operating system device (such as a disk or volume), or the concept (such as a software provider) that the object represents.

Virtual Disk Service (VDS) provider: A concept that models the software responsible for storage management. A VDS software provider performs operations on disk and volume devices exposed to the operating system.

Virtual Disk Service (VDS) session: The point at which a client receives an instance of the VDS service object until the point at which it releases it. Unless otherwise indicated, the term session refers to a VDS session.

Virtual Interface Architecture (VIA): A high-speed interconnect that requires special hardware and drivers provided by third parties.

Voice over IP (VoIP): The use of the Internet Protocol (IP) for transmitting voice communications. VoIP delivers digitized audio in packet form and can be used to transmit over intranets, extranets, and the Internet.

volume: A group of one or more partitions that forms a logical region of storage and the basis for a file system. A volume is an area on a storage device that is managed by the file system as a discrete logical storage unit. A partition contains at least one volume, and a volume can exist on one or more partitions.

volume data: Data stored on a volume.

volume identifier (VolumeId): A 128-bit value used to represent a volume. The value of a VolumeId is unique on a single computer (the local file system or a remote file server).

volume label: See file system label.

volume manager: A system component that manages communication and data transfer between applications and disks.

volume members: See RAID column.

volume mount name: A path for a volume. The path consists of a GUID formatted as a string. Applications can use this path to open the volume.

volume parity – SCSI: See RAID column. See RAID-5.

volume plex: A member of a volume that represents a complete copy of data stored. For instance, mirrored volumes have more than one plex.

volume sequence number (VSN) (for file replication service): A unique sequence number assigned to a change order to order the event sequence in a replica. It is a monotonically increasing sequence number assigned to each change that originates on a given replica member. If one change order has a smaller volume sequence number (VSN) than another change order, the change that the first change order represents occurs before the change that the second change order represents.

VolumeID: A unique identifier that represents the identity of a file system volume.

VolumeInformation: Information about a volume, which is stored on the volume, such as its VolumeID and VolumeSequenceNumber.

VolumeOwner: A MachineID that is considered to be the owner of a VolumeID. A VolumeID can only have one VolumeOwner. For more information, see [MS-DLTM].

VolumeSecret: A value that is used to establish a VolumeOwner. For more information, see [MS-DLTM].

VolumeSequenceNumber: An integer value used to track the sequence of move notification messages received by the protocol server.

VolumeTable: Maps a VolumeID to a RefreshTime, VolumeSequenceNumber, VolumeSecret, and VolumeOwner. For more information, see [MS-DLTM].

vvjoin: See version vector join (vvjoin).