About disk volumes for snapshots and snapshot replication
For snapshots and snapshot replication, all of the volumes in a disk pool must be homogeneous; that is, they must have the same properties. The NetBackup Disk Pool Configuration Wizard enforces compliance, as does the Change Disk Pool dialog box.
The storage administrator defines the properties and the replication topology of the disk volumes. The NetBackup administrator creates disk pools, based on the properties of the volumes.
The volume properties define in what capacity the volumes can be used:
Snapshot
The default property. All volumes that are used for snapshots or snapshot replication must have this property.
Primary
The volume can be used for snapshot creation.
Replication source
The volume can be used as a source for replicating snapshots.
Replication target
The volume can be used as a target for snapshot replication.
Mirror
The volume is a mirror for snapshots. Mirror snapshots have the same life span as the original snapshot.
The replication topology defines the source and the target volumes for replication. For example, volume S1 replicates to T1, volume S2 replicates to T2, and so on.
When you configure your NetBackup disk pools, add the source volumes (Sn) to the disk pool you use for snapshot creation. Then, add the target volumes (Tn) to the disk pool that is the target of the replication.
The Disk Pool Configuration Wizard may not display all of the properties, depending on the underlying volumes.
For example, if a NetApp SnapMirror relationship is not defined at the volume layer, then the Mirror property does not appear in the wizard panel for selection.
Table: Purpose of volume and required volume properties shows the properties that are required for snapshots and snapshot replication volumes, depending on their intended purpose in the NetBackup snapshot and snapshot replication process.
Table: Purpose of volume and required volume properties
Purpose of volume | Snapshot property | Primary property | Replication source property | Replication target property | Mirror property |
|---|---|---|---|---|---|
A volume to contain the initial snapshots of primary data. | X | X | X A primary volume is always a replication source as well. | ||
A volume to serve as a replication source or a replication target. | X | X The Source property allows the volume to serve as a source for snapshot copies. | X The Target property allows the volume to contain copies of snapshots. | X A target volume may have the Mirror property enabled or be Independent. |