# Non-root user behavior
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When you specify a non-root user in your container definition, Amazon ECS automatically configures the Amazon EBS volume with group-based permissions that allow the specified user to read and write to the volume. The volume is mounted with the following characteristics:
+ The volume is owned by the root user and root group.
+ Group permissions are set to allow read and write access.
+ The non-root user is added to the appropriate group to access the volume.

Follow these best practices when using Amazon EBS volumes with non-root containers:
+ Use consistent user IDs (UIDs) and group IDs (GIDs) across your container images to ensure consistent permissions.
+ Pre-create mount point directories in your container image and set appropriate ownership and permissions.
+ Test your containers with Amazon EBS volumes in a development environment to confirm that file system permissions work as expected.
+ If multiple containers in the same task share a volume, ensure they either use compatible UIDs/GIDs or mount the volume with consistent access expectations.