Your company operates an enterprise application on Google Cloud's Compute Engine, which demands both high availability and high performance. The application is mission-critical and is deployed on two instances located in two different zones within the same region, configured in an active-passive mode. This setup ensures that one instance is always ready to take over in case the other one fails. The application relies on a persistent disk to store its data. In the event of a single zone outage, it is crucial that the data stored on the persistent disk is instantly accessible to the instance in the other zone, ensuring minimal downtime and no data loss. Given these requirements, what is the best approach to achieve this?