We have a db.m3.large RDS MySQL instance in us-west-2 w/ multi-AZ that we need to upgrade to a larger instance type (and would like to move to current generation, as well). However, for the last 2 days we can't upgrade to either db.m4.xlarge nor db.m4.2xlarge; when we try (through the console) we get:

Cannot modify the instance class because there are not enough availability zones that have the requested instance class. Please try your request again at a later time. (Service: AmazonRDS; Status Code: 400; Error Code: InsufficientDBInstanceCapacity; Request ID: a1f7a557-0bbb-11e6-bf10-e7d51b83a4d4)

I know this maybe just be that AWS doesn't have capacity there, but given that it's been the case for 2 days now...

I've also wondered if maybe we drop multi-AZ we might be able to upgrade and then re-enable multi-AZ, but that's sort of grasping at straws.

(and I know this may be too much of a support question for serverfault, but I figure it doesn't hurt to ask...)

  • What region are you deployed to? – Tim Apr 26 '16 at 19:27
  • us-west-2 region – denishaskin Apr 27 '16 at 22:05

I think is this likely because our db.m3 is not in a VPC, and db.m4 instances are required to be in a VPC.


in Multi AZ- can you specify what zones because those flavors are not available in all zones.

The following list describes the current Amazon RDS DB instance classes and the Amazon EC2 instance type used for each:

Standard – Latest Generation (db.m4) – Third generation instances that provide more computing capacity than the second generation db.m3 instance classes at a lower price. This DB instance class requires that the DB instance be in a VPC. Note Multi-AZ deployments using db.m4 instance classes are not available in the Asia Pacific (Sydney) region. The db.m4 instance classes are not available for the South America (São Paulo) or China (Beijing) regions.

  • us-west-2 region. – denishaskin Apr 27 '16 at 22:05
  • multi Availability Zone? – Sum1sAdmin Apr 27 '16 at 22:09
  • Yes, it is multi-AZ. – denishaskin Apr 27 '16 at 22:10
  • you know what that means? - if an AWS AZ has a service interruption it moves your RDS to another AZ based on a load balancing algorithm - it's telling you it can't maintain a multi AZ configuration because "there are not enough availability zones that have the requested instance class" - please see my earlier answer. – Sum1sAdmin Apr 27 '16 at 22:15
  • Actually, I think it's the requirement that db.m4 instances be in a VPC. Our existing db.m3 isn't. – denishaskin Apr 27 '16 at 22:23

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