There is a limit on the number of running On-Demand Instances per AWS account per Region. On-Demand Instance limits are managed in terms of the number of vCPUs that your running On-Demand Instances are using, regardless of the instance type. Each limit specifies the vCPU limit for one or more instance families.
- To see the current vCPUs limits of your account from AWS EC2 console
- Enter "vcpu" in the "Find limits" to shortlist the limits
- To find out the current running instances (of the same instance family of the EC2 type you want to check), go to EC2 console.
- Calculate how many vCPUs you nee
- You can use the vCPU limits calculator to see what will be the numbers for adding instances of certain type.
- Request a limit increase
- Even though EC2 automatically increases your On-Demand Instance limits based on your usage, you can request a limit increase if necessary. See Request a limit increase for details.