Best option in Drupal to sync upload content between 2 instances in AWS Load Balancer

Hi,

I have currently setup 2 EC2 server instances with an AWS Elastic Load Balancer. I have a query about how to sync uploaded content files like images between these 2 servers. This is a Drupal website and when content gets uploaded, the files would get uploaded to any 1 of the 2 servers. So how can I sync these files so that they are available on both servers whenever there is a request?

The images are loaded via CloudFront CDN.

Which is the best option for this scenario – Elastic File System (EFS) or S3 or any other alternative?

Note that the mentioned 2 EC2 instances are located in Singapore region, which does not support EFS. So is there any way to access EFS across regions or we are limited to use the region that support EFS?

Thanks

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