Compatibility for resizing instances - Amazon Elastic Compute Cloud

Compatibility for resizing instances

You can resize an instance only if its current instance type and the new instance type that you want are compatible in the following ways:

  • Architecture: AMIs are specific to the architecture of the processor, so you must select an instance type with the same processor architecture as the current instance type. For example:

    • If you are resizing an instance type with a processor based on the Arm architecture, you are limited to the instance types that support a processor based on the Arm architecture, such as C6g and M6g.

    • The following instance types are the only instance types that support 32-bit AMIs: t2.nano, t2.micro, t2.small, t2.medium, c3.large, t1.micro, m1.small, m1.medium, and c1.medium. If you are resizing a 32-bit instance, you are limited to these instance types.

  • Network: Newer instance types must be launched in a VPC. Therefore, you can't resize an instance in the EC2-Classic platform to a instance type that is available only in a VPC unless you have a nondefault VPC. To check whether your instance is in a VPC, check the VPC ID value on the details pane of the Instances screen in the Amazon EC2 console. For more information, see Migrate from EC2-Classic to a VPC.

  • Network adapters: If you switch from a driver for one network adapter to another, the network adapter settings are reset when the operating system creates the new adapter. To reconfigure the settings, you might need access to a local account with administrator permissions. The following are examples of moving from one network adapter to another:

    • AWS PV (T2 instances) to Intel 82599 VF (M4 instances)

    • Intel 82599 VF (most M4 instances) to ENA (M5 instances)

    • ENA (M5 instances) to high-bandwidth ENA (M5n instances)

  • Enhanced networking: Instance types that support enhanced networking require the necessary drivers installed. For example, instances based on the Nitro System require EBS-backed AMIs with the Elastic Network Adapter (ENA) drivers installed. To resize an instance from a type that does not support enhanced networking to a type that supports enhanced networking, you must install the ENA drivers or ixgbevf drivers on the instance, as appropriate.

  • NVMe: EBS volumes are exposed as NVMe block devices on instances built on the Nitro System. If you resize an instance from an instance type that does not support NVMe to an instance type that supports NVMe, you must first install the NVMe drivers on your instance. Also, the device names for devices that you specify in the block device mapping are renamed using NVMe device names (/dev/nvme[0-26]n1).

  • AMI: For information about the AMIs required by instance types that support enhanced networking and NVMe, see the Release Notes in the following documentation: