Connection device rules — resource groups Copy Services scope limiting

Scope limiting determines whether a host is authorized to issue a Copy Services request to a connection device through the application of rules in resource group policies.

Copy Services requests are issued to a destination logical volume or a destination logical subsystem that is specified by the request. That is, the request parameters identify the logical volume or logical subsystem to which the request is to operate. In cases where there is a pair of logical volumes or logical subsystems that are operated on by the Copy Services request (for example, a command to establish a FlashCopy relationship between two volumes), the source entity in the pair is consider the destination entity. The parameters in the request are specified independently of the connection device to which the command is issued.

When the connection device is the same as the destination logical volume, or when the connection device is a logical volume on the destination logical subsystem, the host system has implicit authority to issue the Copy Services request to these destination entities. If the request is to establish a relationship between the destination logical volume (source or primary) and another logical volume (target or secondary), the requested relationship is subject to resource groups policies for Copy Services relationships.

If the command is a remote device command, which specifies a remote device, a peer-to-peer remote copy (PPRC) secondary as the destination device, and if the local device (PPRC primary) is the connection device, the host has implicit authority to issue the Copy Services request to the destination logical volume. (The PPRC relationship was already subjected to validation by resource groups policies.)

If the request is not a remote device command and the destination logical volume is different than the connection volume, or if a destination logical subsystem is not the logical subsystem associated with the connection volume, then the command is said to pass through the connection volume to the destination entity and the authority to issue the request to the destination entity is subject to resource groups policies for pass-through requests.

If the request is a remote device command and the local device (PPRC primary) is different than the connection volume, then the command is said to pass through the connection volume to the local device. The authority to issue the request to the destination device is then subject to resource groups policies for pass-through requests.

Requests that involve global mirror sessions are also subject to resource groups policies, making it possible for session numbers used or masters managed by a Copy Services request to be limited.