Routes that can be used as external paths
A route that uses the local storage system port in the I/O path as a source port.
- To be able to operate safely, it is recommended to perform the external path operations by using CCI. You can specify the command option to suppress a processing that might cause a disconnection from the external storage system to the local storage system for the CCI commands. For more information, see Restrictions on adding an external path to a route in use.
- If you use the Hitachi external storage system, an external path to the external storage system can be added to the same route being used for the external path or the remote path. However, the path from the external storage system might be temporarily disconnected. For more information, see Restrictions on adding an external path to a route in use.
Routes that cannot be used as external paths
When connecting a local storage system and an external storage system using Fibre Channel, the following routes between a port on the local storage system and a port on the external storage system cannot be used as an external path:
- A route being used for an I/O path for which a port on the non-Hitachi external storage system is defined as a source port and a port on the local storage system as a target port. (I/O path indicates a route that issues I/Os to the local storage system from the external storage system, such as the non-Hitachi storage virtualization function, similar to Universal Volume Manager).
- A route that uses the local storage system port in the I/O path as a source port.
If you use a route that cannot be used as an external path, the connection from the external storage system to the local storage system might be disconnected. Use the routes that can be used as external paths.
A route starting from Port A and ending with Port B cannot be used as an external path. If the route starting from Port A and ending with Port B is used as an external path, the I/O path starting from Port B and ending with Port A might be disconnected.
A route starting from Port A and ending with Port C cannot be used as an external path. If the route starting from Port A and ending with Port C is used as an external path, the I/O path starting from Port B and ending with Port A might be disconnected.
