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Veritas NetBackup™ Replication Director Solutions Guide

Last Published: 2017-07-13

Product(s): NetBackup (8.0)

Replication terminology

Use the following table as a reference for understanding many terms that are used frequently when describing replication processes.

Table: Replication terms

Term	Definition
Backup	The process of creating a copy of user data and creating backup images of the data. The process of creating a new tar-formatted backup image of the client's data. The process of creating a snapshot of the client's data.
Cluster Data ONTAP	The operating system that is used on NetApp storage systems in a clustered mode.
Copy	An instance of a NetBackup image which can standalone; it can be read or deleted without affecting any other copy.
Data mover	The mechanism that is used to copy data from storage on the production client to backup storage. Or, to duplicate, the data mover copies data from backup storage to different backup storage. Traditionally, NetBackup functions as the data mover and data travels through clients and media servers. Storage devices can provide more efficient mechanisms to move the data, such as NDMP, built-in replication, or OST (as in Optimized Duplication).
Data ONTAP	The operating system that is used on NetApp storage systems in 7-Mode.
Device	A general term for a logical volume, appliance, or disk array.
Disk array	A disk array which exposes storage or network shares to a host server over SAN, NFS, CIFS, or iSCSI protocols.
Duplication	NetBackup creates a copy by using a media server to move the data or by using the optimized duplication method.
Local domain	The domain in which the storage device resides and in which it is configured.
Mirror	This term can mean either of the following: A disk that maintains an exact copy (duplicate or replica) of another disk. A mirror disk is often called a secondary, and the source disk is called the primary. All writes to the primary disk are also made to the mirror disk. A type of snapshot that is captured on a mirror disk. At the appropriate moment, all further writes to the primary disk are held back from the mirror, which splits the mirror from the primary. As a result of the split, the mirror becomes a snapshot of the primary. The snapshot can then be backed up.
Mount host	The host on which NetBackup mounts a snapshot when NetBackup needs to access the snapshot for any reason. Typically, NetBackup accesses the mount host to browse or to restore backups, or to perform either an Index From Snapshot or a Backup From Snapshot operation in a storage lifecycle policy. To mount a snapshot on a host other than the production client is generally more efficient because it avoids a negative impact on the performance of the production client. Media servers make excellent mount hosts because the media server is both a client and a media server (data mover). As such, NetBackup can often avoid an additional network hop. If no compatible media servers exist, dedicated clients are the next best choice. Note: The mount host and the production client must run the same operating system for the mount host to access the production client. The mount host must be at the same OS version or later. See the NetBackup Snapshot Client Administrator's Guide for more details.
NetApp Plug-in for Veritas NetBackup	Also referred to as the NBUPlugin, this plug-in communicates with the OSTPlugin to query the OnCommand Unified Manager. The NetApp Plug-in for Veritas NetBackup Installation and Administration Guide is available from the NetApp Support Site.
OnCommand Unified Manager (OCUM)	OnCommand Unified Manager (formerly known as DataFabric Manager or DFM) is the software application installed on a host that is identified to be a DataFabric Manager (DFM) server. The software provides infrastructure services such as discovering, monitoring, role-based access controls, auditing, and logging for products in the Data and Storage suites.
NetApp Management Console	The NetApp interface that is used to configure and manage the OnCommand Unified Manager.
NetBackup OpenStorage Plug-in for Replication Director	Also referred to as the OSTPlugin, NetBackup uses this to communicate with the vendor's plug-in.
OST device	A storage server that has implemented the OST plug-in interface.
Point-in-time rollback	A snapshot is a point-in-time, disk-based copy of a file system or volume. A restore from a snapshot rolls the entire file system or volume back to a specific point in time. Therefore, a snapshot restore is called restoring from a Point-in-time rollback. All of the data in the snapshot is restored. Any data changes or snapshots that were made after that point-in-time are lost.
Primary volume	A unit of storage space that a disk array exposes to a host in the form of a network share (NFS or CIFS) or LUN block device. Primary volumes store an application's active data.
Replica	A replica is a block copy of the snapshot.
Replication	The process of replicating a snapshot onto a separate disk array using NetBackup Replication Director.
Replication source	A NetBackup-configured disk pool and storage unit that contains the volumes that serve as the source for subsequent replications.
Replication target	A NetBackup-configured disk pool and storage unit that can receive or accept replications from a replication source.
Snapshot	A point-in-time, read-only, disk-based copy of a client volume or of a filer. A snapshot is created with minimal impact on other applications. NetBackup provides several types of snapshots, depending on the device where the snapshot occurs. An image copy that is a snapshot is also considered a replica. A snapshot copy consists of one or more snapshot fragments.
Snapshot method	A set of routines for creating a snapshot. The NetBackup administrator can select the method, or let NetBackup select it when the snapshot begins (auto method).
Snapshot mirror	A disk mirror that is an exact replica of a primary volume at a particular moment, reproduced on a physically separate device.
Snapshot source	The production data (file system, raw partition, or logical volume) to which a snapshot method is applied. NetBackup automatically selects the snapshot source according to the entries in the Backup Selections list of the snapshot policy.
Storage device	See disk array.
Storage lifecycle policy (SLP)	NetBackup uses storage lifecycle policies to manage the lifecycle of a backup or snapshot image. An SLP controls the image migration, duplication, and replication within a single NetBackup master server domain.
SVM	Storage virtual machines. These were formerly known as Vservers.
Storage unit	A storage unit is configured for one of two types of data: Backup storage units contain backup images. A backup storage unit cannot contain snapshots. Snapshot storage units contain snapshots. A snapshot storage unit cannot contain backups. Replication Director uses snapshot storage units in snapshot replication configurations.
Storage server	A storage device that is configured in NetBackup. A storage server is a NetBackup entity that represents a disk array.
vFiler	vFilers are ONTAP 7-mode virtual containers that create separate virtual filer instances withing a physical controller (doesn't matter if FAS or V-Series).