A multi-path input-output (MPIO) driver in a host server reduces host-copy migration data transmission rate based on decrease in foreground IO response time. A baseline foreground IO response time measured before commencement of the host-copy migration is compared with a reference foreground IO response time measured after commencement of the host-copy migration. Increase in the foreground IO response time, expressed as a percentage or time value, that satisfies a predetermined limit will trigger reduction of the host-copy migration data transmission rate. The reference foreground IO response time is repeatedly measured and updated each time the host-copy migration data transmission rate is decreased.