Before mapping a command device as a remote command device, note the following information:
- The remote command device cannot be identified by port discovery or volume discovery process that takes place during the mapping operation.
- When an external storage system (A) has a remote command device (B) (that is, when a command device in another external storage system (C) is mapped to this external storage system (A)), make sure that the remote command device (B) does not have the smallest LUN on the port in the external storage system (A).
- You cannot send I/O to the remote command device.
- You cannot receive I/O from the remote command device.
- You cannot set command device disable on the remote command device.
- You cannot set command device security on the remote command device.
- Do not set the command device security on the external storage system side for the command device that is mapped as a remote command device.
- You cannot create CVs in the remote command device.
- Command device information reported to the local host by the remote command device includes the following:
- Serial number
- Vendor
- Device name. The name displayed for many individual storage systems is listed in Supported external system path mode for external volumes.
- Errors can occur when operations are performed on the remote command device, even though the status of the remote command device is normal. In this case, check the status of the command device on the external storage system where the error actually exists.