Hitachi Universal Volume Manager enables you to connect volumes in external storage systems to your storage system, and manage those volumes as if they were one system.
Typically, if a system consists of multiple storage systems, the host must be connected to each of the storage systems. When configuring the connections from the host to the volumes, the system administrator must follow specific instructions for each of the storage systems.
With Universal Volume Manager, the administrator configures the connection from the host to your storage system, and then uses mapped volumes in an external storage system in the same way as volumes in the local storage system.
With Universal Volume Manager, you can perform all procedures in external storage with the same Hitachi software as when you use the local storage system.
For example, you can use a replication program to perform copy operations between the local storage system and external systems, including the following:
- Copying data from a volume in the local storage system to a volume in the external system
- Copying data from a volume in one external system to a volume in another external system
The image below describes the copy operations before and after installation of Universal Volume Manager.
The image below describes the copy operation between the host and multiple storage systems.
Universal Volume Manager consists of several components, including the following:
- A local storage system
- Hitachi Virtual Storage Platform G350, G370, G700, G900, Hitachi Virtual Storage Platform F350, F370, F700, F900, or
- Hitachi Virtual Storage Platform G1x00 or Hitachi Virtual Storage Platform F1500
- One or more external storage systems
The local storage system can connect to many different storage systems, including ones manufactured by Hitachi, IBM®, and EMC. Hosts recognize the volumes in these systems as internal volumes of the local storage system.
A volume in an external storage system that is mapped to the local storage system is referred to as a mapped external volume. After an external volume is mapped, it is used as an internal volume, which is a virtual representation of the external volume.
A volume managed by the local storage system. An internal volume can be a physical volume or the virtual representation of an external volume.
- Logical devices (LDEVs)
- External path
- Mapping path
The following figure provides an overview of these components:
How Universal Volume Manager works
When you map to a volume in an external storage system, it becomes an internal volume in the local storage system.
- A local system port must be connected to the external storage system port with a Fibre Channel cable. This route between ports is the external path.
- The external volume is represented in the local storage system as an internal volume, and the path between them is the mapping path.
- The figure below shows the connection between the local and external storage systems. In this figure, the external system is connected to the local system's external ports via a switch. External port is an attribute assigned to ports on the local storage system.
You can connect multiple external storage systems to one external port even if the external port is already in use.
You can create LDEVs in two different ways:
- By using Universal Volume Manager during mapping
- By using the Virtual LVI/LUN (VLL) function after mapping. In this case, the internal volume (the internal volume to which an external volume is mapped) is the virtual device (VDEV) and the LDEV in the external volume is the LDEV.
As shown in the figure above, you must have LDEVs in the mapped external volumes for use in the local system.