Upgrading the storage file system for a DB instance - Amazon Relational Database Service

Upgrading the storage file system for a DB instance

Most RDS DB instances offer a maximum storage size of 64 TiB for RDS for MariaDB, MySQL, and PostgreSQL databases. However, some older 32-bit file systems have lower storage capacities. To determine the storage capacity of your DB instance, you can use the describe-valid-db-instance-modifications AWS CLI command.

If RDS detects that one of your DB instances is running an older file system (one that has a 16 TiB storage size, a file size limit of 2 TiB, or non-optimized writes), the RDS console informs you that your file system configuration is eligible for an upgrade. You can check the upgrade eligibility of your DB instance on the Storage panel of the DB instance details page.

Check the storage configuration upgrade eligibility of a DB instance.

If your DB instance is eligible for a file system upgrade, you can perform the upgrade in one of two ways:

  • Create a blue/green deployment and specify Upgrade storage file system configuration. This option upgrades the file system in the green environment to the preferred configuration. You can then switch over the blue/green deployment, which promotes the green environment to be the new production environment. For detailed instructions, see Creating a blue/green deployment.

  • Create a DB instance read replica and specify Upgrade storage file system configuration. This option upgrades the file system of the read replica to the preferred configuration. You can then promote the read replica to be a standalone instance. For detailed instructions, see Creating a read replica.

Upgrading the storage configuration is an I/O-intensive operation and leads to longer creation times for read replicas and blue/green deployments. The storage upgrade process is faster if the source DB instance uses Provisioned IOPS SSD (io1 or io2 Block Express) storage and you provisioned the green environment or read replica with an instance size of 4xlarge or larger. Storage upgrades involving General Purpose SSD (gp2) storage can deplete your I/O credit balance, resulting in longer upgrade times. For more information, see Amazon RDS DB instance storage.

During the storage upgrade process, the database engine isn't available. If the storage consumption on your source DB instance is greater than or equal to 90% of the allocated storage size, and if storage autoscaling is enabled, the storage upgrade process increases the allocated storage size by 10% for the green instance or read replica. If storage autoscaling is disabled, the storage size doesn't increase during the upgrade.