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3-6 Preparing for Universal Volume Manager Operations
Hitachi Universal Storage Platform V/VM Universal Volume Manager User’s Guide
Guidelines for Universal Volume Manager Operations This section provides guidelines for the Universal Volume Manager operations.
Mapping Guidelines
• Before mapping external volumes, make sure that external volumes are
not reserved by a host.
External volumes that are reserved by a host cannot be mapped as internal
volumes. If external volumes are reserved by a host, cancel the reserve
settings and then map the external volumes.
• Once external volumes are mapped, do not reserve the external volumes
for a host .
If external volumes are reserved by a host , internal volumes to which the
external volumes are mapped will be blocked .
• Make sure that an external volume is accessed only from the local storage
system side once the external volume is mapped.
– Make sure that the external volume, which has been mapped as an
internal volume, is not accessed from the host that is connected to the
external storage system.
– Make sure that the external volume, which has been mapped as an
internal volume, is not manipulated by copy function or some other
functions of the external storage system.
Hosts can access the external storage system volumes that have not been
mapped as the internal volumes. There is no restriction.
• Do not map multiplatform volumes of external storage systems as internal
volumes.
• When an external storage system that has an ownership is connected to
USP V/VM storage system, configure the cross-subsystem path to the
primary controller in the external storage system as primary path.
Ownership is an exclusive right to control volumes. A controller that has an
ownership is called a primary controller. If a cross-subsystem path to a
controller without ownership is configured as primary path, the ownership
will be transferred and it may affect the performance.