The condition of SFP transceivers of RDF port pairs is monitored and used to project port pair data transmission rate degradation. Responsive to receipt of a command to migrate data from a source volume to a target volume, ability of port pairs to accommodate the additional load associated with data migration is calculated based on projected data transmission rate and normal load. Only port pairs that are capable of accommodating the additional load in view of the condition of the SFP transceivers are considered as candidates. Utilization of the source volume is monitored and the target volume is created with a size based on projected growth of utilization of the source volume.