In the instance of hot swapping, not all fans are able to start up at the same time since the goal is to mitigate system down time. Instead, the easiest solution to prevent reverse rotation is to reduce the speed on all active fans while inserting the new fan. The reduced airflow will have less impact on reverse rotation of the fan and will allow the new fan to start up normally. Once the new fan has reached adequate speed, the rest of the fans can be returned to normal operating speed. This option is often the easiest solution since it does not require extra investment in equipment and can be added to almost any system.