Dedicated Instances - Amazon Elastic Compute Cloud
Dedicated Instance BasicsWorking with Dedicated Instances

Dedicated Instances

Dedicated Instances are Amazon EC2 instances that run in a virtual private cloud (VPC) on hardware that's dedicated to a single customer. Dedicated Instances that belong to different AWS accounts are physically isolated at a hardware level, even if those accounts are linked to a single payer account. However, Dedicated Instances may share hardware with other instances from the same AWS account that are not Dedicated Instances.

Note

A Dedicated Host is also a physical server that's dedicated for your use. With a Dedicated Host, you have visibility and control over how instances are placed on the server. For more information, see Dedicated Hosts.

Dedicated Instance Basics

Each instance that you launch into a VPC has a tenancy attribute. This attribute has the following values.

Tenancy Value Description

default

Your instance runs on shared hardware.

dedicated

Your instance runs on single-tenant hardware.

host

 Your instance runs on a Dedicated Host, which is an isolated server with configurations that you can control.

After you launch an instance, there are some limitations to changing its tenancy.

  • You cannot change the tenancy of an instance from default to dedicated or host after you've launched it.

  • You cannot change the tenancy of an instance from dedicated or host to default after you've launched it.

You can change the tenancy of an instance from dedicated to host, or from host to dedicated after you've launched it. For more information, see Changing the Tenancy of an Instance.

Each VPC has a related instance tenancy attribute. This attribute has the following values.

Tenancy Value Description

default

An instance launched into the VPC runs on shared hardware by default, unless you explicitly specify a different tenancy during instance launch.

dedicated

An instance launched into the VPC is a Dedicated Instance by default, unless you explicitly specify a tenancy of host during instance launch. You cannot specify a tenancy of default during instance launch.

You can change the instance tenancy of a VPC from dedicated to default after you create it. You cannot change the instance tenancy of a VPC from default to dedicated after it is created.

To create Dedicated Instances, you can do the following:

  • Create the VPC with the instance tenancy set to dedicated (all instances launched into this VPC are Dedicated Instances).

  • Create the VPC with the instance tenancy set to default, and specify a tenancy of dedicated for any instances when you launch them.

Dedicated Instances Limitations

Some AWS services or their features won't work with a VPC with the instance tenancy set to dedicated. Check the service's documentation to confirm if there are any limitations.

Some instance types cannot be launched into a VPC with the instance tenancy set to dedicated. For more information about supported instances types, see Amazon EC2 Dedicated Instances.

Amazon EBS with Dedicated Instances

When you launch an Amazon EBS-backed Dedicated Instance, the EBS volume doesn't run on single-tenant hardware.

Reserved Instances with Dedicated Tenancy

To guarantee that sufficient capacity is available to launch Dedicated Instances, you can purchase Dedicated Reserved Instances. For more information, see Reserved Instances.

When you purchase a Dedicated Reserved Instance, you are purchasing the capacity to launch a Dedicated Instance into a VPC at a much reduced usage fee; the price break in the usage charge applies only if you launch an instance with dedicated tenancy. When you purchase a Reserved Instance with default tenancy, it applies only to a running instance with default tenancy; it would not apply to a running instance with dedicated tenancy.

You can't use the modification process to change the tenancy of a Reserved Instance after you've purchased it. However, you can exchange a Convertible Reserved Instance for a new Convertible Reserved Instance with a different tenancy.

Automatic Scaling of Dedicated Instances

You can use Amazon EC2 Auto Scaling to launch Dedicated Instances. For more information, see Launching Auto Scaling Instances in a VPC in the Amazon EC2 Auto Scaling User Guide.

Automatic Recovery of Dedicated Instances

You can configure automatic recovery for a Dedicated Instances if it becomes impaired due to an underlying hardware failure or a problem that requires AWS involvement to repair. For more information, see Recover your instance.

Dedicated Spot Instances

You can run a Dedicated Spot Instance by specifying a tenancy of dedicated when you create a Spot Instance request. For more information, see Specifying a tenancy for your Spot Instances.

Pricing for Dedicated Instances

Pricing for Dedicated Instances is different to pricing for On-Demand Instances. For more information, see the Amazon EC2 Dedicated Instances product page.

Burstable Performance Instances with Dedicated Instances

You can leverage the benefits of running on dedicated tenancy hardware with Burstable performance instances. T3 Dedicated Instances launch in unlimited mode by default, and they provide a baseline level of CPU performance with the ability to burst to a higher CPU level when required by your workload. The T3 baseline performance and ability to burst are governed by CPU credits. Because of the burstable nature of the T3 instance types, we recommend that you monitor how your T3 instances use the CPU resources of the dedicated hardware for the best performance. T3 Dedicated Instances are intended for customers with diverse workloads that display random CPU behavior, but that ideally have average CPU usage at or below the baseline usages. For more information, see CPU credits and baseline utilization for burstable performance instances.

Amazon EC2 has systems in place to identify and correct variability in performance. However, it is still possible to experience short term variability if you launch multiple T3 Dedicated Instances that have correlated CPU usage patterns. For these more demanding or correlated workloads, we recommend using M5 or M5a Dedicated Instances rather than T3 Dedicated Instances.

Working with Dedicated Instances

You can create a VPC with an instance tenancy of dedicated to ensure that all instances launched into the VPC are Dedicated Instances. Alternatively, you can specify the tenancy of the instance during launch.

Creating a VPC with an Instance Tenancy of Dedicated

When you create a VPC, you have the option of specifying its instance tenancy. If you're using the Amazon VPC console, you can create a VPC using the VPC wizard or the Your VPCs page.

To create a VPC with an instance tenancy of dedicated (VPC Wizard)

  1. Open the Amazon VPC console at https://console.aws.amazon.com/vpc/.

  2. From the dashboard, choose Start VPC Wizard.

  3. Select a VPC configuration, and then choose Select.

  4. On the next page of the wizard, choose Dedicated from the Hardware tenancy list.

  5. Choose Create VPC.

To create a VPC with an instance tenancy of dedicated (Create VPC dialog box)

  1. Open the Amazon VPC console at https://console.aws.amazon.com/vpc/.

  2. In the navigation pane, choose Your VPCs, and then Create VPC.

  3. For Tenancy, choose Dedicated. Specify the CIDR block, and choose Yes, Create.

To set the tenancy option when you create a VPC using the command line

If you launch an instance into a VPC that has an instance tenancy of dedicated, your instance is automatically a Dedicated Instance, regardless of the tenancy of the instance.

Launching Dedicated Instances into a VPC

You can launch a Dedicated Instance using the Amazon EC2 launch instance wizard.

To launch a Dedicated Instance into a default tenancy VPC using the console

  1. Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

  2. Choose Launch Instance.

  3. On the Choose an Amazon Machine Image (AMI) page, select an AMI and choose Select.

  4. On the Choose an Instance Type page, select the instance type and choose Next: Configure Instance Details.

    Note

    Ensure that you choose an instance type that's supported as a Dedicated Instance. For more information, see Amazon EC2 Dedicated Instances.

  5. On the Configure Instance Details page, select a VPC and subnet. Choose Dedicated - Run a dedicated instance from the Tenancy list, and then Next: Add Storage.

  6. Continue as prompted by the wizard. When you've finished reviewing your options on the Review Instance Launch page, choose Launch to choose a key pair and launch the Dedicated Instance.

For more information about launching an instance with a tenancy of host, see Launching instances onto a Dedicated Host.

To set the tenancy option for an instance during launch using the command line

Displaying Tenancy Information

To display tenancy information for your VPC using the console

  1. Open the Amazon VPC console at https://console.aws.amazon.com/vpc/.

  2. In the navigation pane, choose Your VPCs.

  3. Check the instance tenancy of your VPC in the Tenancy column.

  4. If the Tenancy column is not displayed, choose Edit Table Columns (the gear-shaped icon), Tenancy in the Show/Hide Columns dialog box, and then Close.

To display tenancy information for your instance using the console

  1. Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

  2. In the navigation pane, choose Instances.

  3. Check the tenancy of your instance in the Tenancy column.

  4. If the Tenancy column is not displayed, do one of the following:

    • Choose Show/Hide Columns (the gear-shaped icon), Tenancy in the Show/Hide Columns dialog box, and then Close.

    • Select the instance. The Description tab in the details pane displays information about the instance, including its tenancy.

To describe the tenancy of your VPC using the command line

To describe the tenancy of your instance using the command line

To describe the tenancy value of a Reserved Instance using the command line

To describe the tenancy value of a Reserved Instance offering using the command line

Changing the Tenancy of an Instance

Depending on your instance type and platform, you can change the tenancy of a stopped Dedicated Instance to host after launching it. The next time the instance starts, it's started on a Dedicated Host that's allocated to your account. For more information about allocating and working with Dedicated Hosts, and the instance types that can be used with Dedicated Hosts, see Working with Dedicated Hosts. Similarly, you can change the tenancy of a stopped Dedicated Host instance to dedicated after launching it. The next time the instance starts, it's started on single-tenant hardware that we control.

To change the tenancy of an instance using the console

  1. Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

  2. In the navigation pane, choose Instances and select your instance.

  3. Choose Instance state, Stop instance.

  4. Choose Actions, Instance settings, Modify instance placement.

  5. In the Tenancy list, choose whether to run your instance on dedicated hardware or on a Dedicated Host. Choose Save.

To modify the tenancy value of an instance using the command line

Changing the Tenancy of a VPC

You can change the instance tenancy attribute of a VPC from dedicated to default. Modifying the instance tenancy of the VPC does not affect the tenancy of any existing instances in the VPC. The next time you launch an instance in the VPC, it has a tenancy of default, unless you specify otherwise during launch.

You cannot change the tenancy attribute of a VPC from default to dedicated after it is created.

You can modify the instance tenancy attribute of a VPC using the AWS CLI, an AWS SDK, or the Amazon EC2 API only.

To modify the instance tenancy attribute of a VPC using the AWS CLI

  • Use the modify-vpc-tenancy command to specify the ID of the VPC and instance tenancy value. The only supported value is default. 

    aws ec2 modify-vpc-tenancy --vpc-id vpc-1a2b3c4d --instance-tenancy default