How to fix «Insufficient capacity» on starting an instance in AWS EC2?



If you get this error when you try to launch an instance or restart a stopped instance, AWS does not currently have enough available On-Demand capacity to fulfill your request.


To resolve the issue, try the following:

  • Wait a few minutes and then submit your request again; capacity can shift frequently.
  • Submit a new request with a reduced number of instances.
    For example, if you're making a single request to launch 15 instances, try making 3 requests for 5 instances, or 15 requests for 1 instance instead.
  • If you're launching an instance, submit a new request without specifying an Availability Zone.
  • If you're launching an instance, submit a new request using a different instance type (which you can resize at a later stage). For more information, see Change the instance type.
  • If you are launching instances into a cluster placement group, you can get an insufficient capacity error. For more information, see Placement group rules and limitations.