Term	Description
Local storage system	The local storage system is the storage system that you are acting upon. When you see Primary in the Local Role column, it indicates that the storage system contains the volume that holds the primary role in the mirror relationship. When you see Secondary in the Local Role column, it indicates that the storage system contains the volume that holds the secondary role in the mirror relationship.
Mirrored pair	A mirrored pair is comprised of two volumes, a primary volume and a secondary volume.
Primary volume	The primary volume of a mirrored pair is the source volume to be mirrored.
Recovery point objective (RPO)	Recovery Point Objective (RPO) represents an objective that indicates the difference considered acceptable between the primary volume and secondary volume in a mirrored pair. An RPO of zero indicates that no difference between the primary volume and secondary volume can be tolerated. An RPO greater than zero indicates that the secondary volume is less current or lags behind the primary volume.
Remote storage system	The remote storage system is usually designated as the secondary site, which usually holds a replica of the data in a mirroring configuration.
Reserved capacity	Reserved capacity is the physical allocated capacity that is used for any copy service operation and storage object. It is not directly readable by the host.
Role change	Role change is assigning the primary role to the secondary volume and vice versa.
Secondary volume	The secondary volume of a mirrored pair is usually located at a secondary site and holds a replica of the data.
Synchronization	Synchronization occurs at initial synchronization between the local storage system and the remote storage system. Synchronization also occurs when the primary and secondary volumes become unsynchronized after a communication interruption. When the communication link is working again, any unreplicated data is synchronized to the secondary volume’s storage system.

Term

Description

Local storage system

The local storage system is the storage system that you are acting upon.

When you see Primary in the Local Role column, it indicates that the storage system contains the volume that holds the primary role in the mirror relationship. When you see Secondary in the Local Role column, it indicates that the storage system contains the volume that holds the secondary role in the mirror relationship.

Mirrored pair

A mirrored pair is comprised of two volumes, a primary volume and a secondary volume.

Primary volume

The primary volume of a mirrored pair is the source volume to be mirrored.

Recovery point objective (RPO)

Recovery Point Objective (RPO) represents an objective that indicates the difference considered acceptable between the primary volume and secondary volume in a mirrored pair. An RPO of zero indicates that no difference between the primary volume and secondary volume can be tolerated. An RPO greater than zero indicates that the secondary volume is less current or lags behind the primary volume.

Remote storage system

The remote storage system is usually designated as the secondary site, which usually holds a replica of the data in a mirroring configuration.

Reserved capacity

Reserved capacity is the physical allocated capacity that is used for any copy service operation and storage object. It is not directly readable by the host.

Role change

Role change is assigning the primary role to the secondary volume and vice versa.

Secondary volume

The secondary volume of a mirrored pair is usually located at a secondary site and holds a replica of the data.

Synchronization

Synchronization occurs at initial synchronization between the local storage system and the remote storage system. Synchronization also occurs when the primary and secondary volumes become unsynchronized after a communication interruption. When the communication link is working again, any unreplicated data is synchronized to the secondary volume’s storage system.