How do I troubleshoot InsufficientInstanceCapacity errors when starting or launching an EC2 instance?

Last updated: 2021-07-13

If AWS doesn't currently have enough available On-Demand capacity to complete your request, you'll receive the following InsufficientInstanceCapacity error:

"An error occurred (InsufficientInstanceCapacity) when calling the RunInstances operation (reached max retries: 4). We currently do not have sufficient capacity in the Availability Zone you requested."

If you receive this error, do the following:

• For troubleshooting steps, see Insufficient instance capacity.
• If the preceding troubleshooting steps don't resolve the problem, then you can move the instance to another VPC or to another subnet and Availability Zone.

To avoid insufficient capacity errors on critical machines, consider using On-Demand Capacity Reservations. To use an On-Demand Capacity Reservation, do the following:

1. Create the Capacity Reservation in an Availability Zone.
2. Launch critical instances into your Capacity Reservation. You can view real-time Capacity Reservation usage, and launch instances into it as needed.