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Perform following to update permission for EBS RDS availability zones :
Login to the AWS Management Console at https://console.aws.amazon.com as root user.
Navigate to RDS console.
In the navigation pane, Click on Databases.
Click on the Database instance to be modified, click Modify.
Under Instance Specifications, set Multi-AZ deployment as Yes.
Click on the Continue.
Under Scheduling of modifications, select Apply Immediately.
Click on Modify DB Instance.
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