Problem Upgrading PostGreSQL RDS


I have a PostgreSQL RDS v 11.22 on a db.t2.medium. I have to upgrade the database version and the instance type and the cert. I'm trying to do this but I'm getting the following error. I have gone to the db instance, selected Modify, changed the DB engine version to 15.5 and the instance class to db.t3.medium, I'm also upgrading the certificate to the new default one.

It then shows a screen confirming my changes and when I say Modify I get the error below:

We're sorry, your request to modify DB instance mediofficedb has failed. RDS does not support creating a DB instance with the following combination: DBInstanceClass=db.t2.medium, Engine=postgres, EngineVersion=15.5, LicenseModel=postgresql-license. For supported combinations of instance class and database engine version, see the documentation.

But I can CLEARLY see I have selected db.t3.medium.

2 Answers

If the AWS Management Console is not processing your request correctly, consider using the AWS Command Line Interface (CLI) or one of the AWS SDKs to modify your DB instances:

aws rds modify-db-instance \
    --db-instance-identifier your-instance-identifier \
    --db-instance-class db.t3.medium \
    --engine-version 15.5 \
    --ca-certificate-identifier your-new-certificate-identifier \


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answered 2 months ago

I was able to replicate the issue and got the same error message. As a workaround, I performed the upgrade in 2-steps. First, I upgraded the instance class to t3.medium and then performed the upgrade for engine version to 15.5.

I ran a query to check the supported instance classes for PostgreSQL 15.5 and observed that db.t2.medium was not a supported instance class. Hence, I performed the upgrade in two steps.

Hope this helps!


aws rds describe-orderable-db-instance-options --engine postgres --engine-version 15.5 --query "*[].{DBInstanceClass:DBInstanceClass,StorageType:StorageType}|[?StorageType=='gp2']|[].{DBInstanceClass:DBInstanceClass}" --output text


db.m5.12xlarge db.m5.16xlarge db.m5.24xlarge db.m5.2xlarge db.m5.4xlarge db.m5.8xlarge db.m5.large db.m5.xlarge db.m6g.12xlarge db.m6g.16xlarge db.m6g.2xlarge db.m6g.4xlarge db.m6g.8xlarge db.m6g.large db.m6g.xlarge db.m6i.12xlarge db.m6i.16xlarge db.m6i.24xlarge db.m6i.2xlarge db.m6i.32xlarge db.m6i.4xlarge db.m6i.8xlarge db.m6i.large db.m6in.12xlarge db.m6in.16xlarge db.m6in.24xlarge db.m6in.2xlarge db.m6in.32xlarge db.m6in.4xlarge db.m6in.8xlarge db.m6in.large db.m6in.xlarge db.m6i.xlarge db.m7g.12xlarge db.m7g.16xlarge db.m7g.2xlarge db.m7g.4xlarge db.m7g.8xlarge db.m7g.large db.m7g.xlarge db.r5.12xlarge db.r5.16xlarge db.r5.24xlarge db.r5.2xlarge db.r5.4xlarge db.r5.8xlarge db.r5b.12xlarge db.r5b.16xlarge db.r5b.24xlarge db.r5b.2xlarge db.r5b.4xlarge db.r5b.8xlarge db.r5b.large db.r5b.xlarge db.r5.large db.r5.xlarge db.r6g.12xlarge db.r6g.16xlarge db.r6g.2xlarge db.r6g.4xlarge db.r6g.8xlarge db.r6g.large db.r6g.xlarge db.r6i.12xlarge db.r6i.16xlarge db.r6i.24xlarge db.r6i.2xlarge db.r6i.32xlarge db.r6i.4xlarge db.r6i.8xlarge db.r6i.large db.r6in.12xlarge db.r6in.16xlarge db.r6in.24xlarge db.r6in.2xlarge db.r6in.32xlarge db.r6in.4xlarge db.r6in.8xlarge db.r6in.large db.r6in.xlarge db.r6i.xlarge db.r7g.12xlarge db.r7g.16xlarge db.r7g.2xlarge db.r7g.4xlarge db.r7g.8xlarge db.r7g.large db.r7g.xlarge db.t3.2xlarge db.t3.large db.t3.medium db.t3.micro db.t3.small db.t3.xlarge db.t4g.2xlarge db.t4g.large db.t4g.medium db.t4g.micro db.t4g.small db.t4g.xlarge db.x2g.12xlarge db.x2g.16xlarge db.x2g.2xlarge db.x2g.4xlarge db.x2g.8xlarge db.x2g.large db.x2g.xlarge

answered a month ago

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