Provided are a method, system, and program for initiating and using
information used for a host, control unit, and logical device connections
receiving a request to create a host port to control unit port
connection. In a volume group data structure, a volume group entry is
defined having a plurality of pointers for the host port and control unit
port pair. At least one device address is added to the volume group that
is accessible to the host port and control unit port connection by
initializing at least one pointer in the volume group entry to address at
least one device data structure. For each of the at least one device
addresses, indication is made in the at least one device data structure
addressed by the at least one pointer in the volume group entry that the
device address is accessible to the host port and control unit port
connection.