---
title: "RDS instances do not have Multi-AZ enabled"
canonical: "https://kb.cynergy.app/space/MD/1210056705/RDS%20instances%20do%20not%20have%20Multi-AZ%20enabled"
format: markdown
---
# Description

Amazon RDS Multi-AZ deployments improve database availability and durability within a single region by automatically failing over to a standby replica in a different Availability Zone during planned or unplanned outages. Key benefits include enhanced data durability, increased availability, protection of database performance, and automatic failover to maintain seamless operations.

# Fix - Runtime

## AWS Console

1. Log in to the AWS Management Console at [https://console.aws.amazon.com/](https://console.aws.amazon.com/).
2. Open the **[Amazon RDS console](https://console.aws.amazon.com/rds/)**.
3. To create a new Multi-AZ deployment using the AWS Management Console, simply click the "Yes" option for "Multi-AZ Deployment" when launching a DB Instance.
4. To convert an existing Single-AZ DB Instance to a Multi-AZ deployment, use the "Modify" option corresponding to your DB Instance in the AWS Management Console.

## CLI Command

If you use the `create-db-instance` AWS CLI command to create a Multi-AZ DB instance, set the `--multi-az` parameter to `true`. If you use the CreateDBInstance API operation, set the `MultiAZ` parameter to `true`. You can't set the `AvailabilityZone` parameter if the DB instance is a Multi-AZ deployment.

```
aws rds create-db-instance \
    --db-instance-identifier test-mysql-instance \
    --db-instance-class db.t3.micro \
    --engine mysql \
    --master-username admin \
    --master-user-password secret99 \
    --allocated-storage 20 \
    --multi-az true

```

# Fix - Build time

## Terraform

- **Resource**: aws_db_instance
- **Argument**: multi_az - Specifies if the RDS instance is Multi-AZ.

```
resource "aws_db_instance" "default" {
  ...
  name                 = "mydb"
+ multi_az             = true 
}

```

## CloudFormation

- **Resource**: AWS::RDS::DBInstance
- **Argument**: Properties.MultiAZ

```
Resources:
  MyDBEnabled:
    Type: 'AWS::RDS::DBInstance'
    Properties:
      ...
+     MultiAZ: true
```