# Amazon EC2 Dedicated Instances By default, EC2 instances run on shared tenancy hardware. This means that multiple AWS accounts might share the same physical hardware. Dedicated Instances are EC2 instances that run on hardware that's dedicated to a single AWS account. This means that Dedicated Instances are physically isolated at the host hardware level from instances that belong to other AWS accounts, even if those accounts are linked to a single payer account. However, Dedicated Instances might share hardware with other instances from the same AWS account that are not Dedicated Instances. Dedicated Instances provide no visibility or control over instance placement, and they do not support host affinity. If you stop and start a Dedicated Instance, it might not run on the same host. Similarly, you cannot target a specific host on which to launch or run an instance. Additionally, Dedicated Instances provide limited support for Bring Your Own License (BYOL). If you require visibility and control over instance placement and more comprehensive BYOL support, consider using a Dedicated Host instead. Dedicated Instances and Dedicated Hosts can both be used to launch Amazon EC2 instances onto dedicated physical servers. There are no performance, security, or physical differences between Dedicated Instances and instances on Dedicated Hosts. However, there are some key differences between them. The following table highlights some of the key differences between Dedicated Instances and Dedicated Hosts: | | Dedicated Host | Dedicated Instance | | --- | --- | --- | | Dedicated physical server | Physical server with instance capacity fully dedicated to your use. | Physical server that's dedicated to a single customer account. | | Instance capacity sharing | Can share instance capacity with other accounts. | Not supported | | Billing | Per-host billing | Per-instance billing | | Visibility of sockets, cores, and host ID | Provides visibility of the number of sockets and physical cores | No visibility | | Host and instance affinity | Allows you to consistently deploy your instances to the same physical server over time | Not supported | | Targeted instance placement | Provides additional visibility and control over how instances are placed on a physical server | Not supported | | Automatic instance recovery | Supported. For more information, see [Amazon EC2 Dedicated Host recovery](dedicated-hosts-recovery.md). | Supported | | Bring Your Own License (BYOL) | Supported | Partial support \$1 | | Capacity Reservations | Not supported | Supported | \$1 Microsoft SQL Server with License Mobility through Software Assurance, and Windows Virtual Desktop Access (VDA) licenses can be used with Dedicated Instance. For more information, see [Amazon EC2 Dedicated Hosts](dedicated-hosts-overview.md). **Topics** + [Dedicated Instance basics](#dedicated-howitworks) + [Supported features](#features) + [Dedicated Instances limitations](#dedicated-limits) + [Pricing for Dedicated Instances](#dedicated-instance-pricing) + [Launch Dedicated Instances](dedicatedinstancesintovpc.md) + [Change the tenancy of an instance](dedicated-change-tenancy.md) + [Change the tenancy of a VPC](change-tenancy-vpc.md) ## Dedicated Instance basics A VPC can have a tenancy of either `default` or `dedicated`. By default, your VPCs have `default` tenancy and instances launched into a `default` tenancy VPC have `default` tenancy. To launch Dedicated Instances, do the following: + Create a VPC with a tenancy of `dedicated`, so that all instances in the VPC run as Dedicated Instances. For more information, see [Launch Dedicated Instances into a VPC with default tenancy](dedicatedinstancesintovpc.md). + Create a VPC with a tenancy of `default` and manually specify a tenancy of `dedicated` for the instances to run as Dedicated Instances. For more information, see [Launch Dedicated Instances into a VPC with default tenancy](dedicatedinstancesintovpc.md). ## Supported features Dedicated Instances support the following features and AWS service integrations: **Topics** + [Reserved Instances](#dedicatedreservedinstances) + [Automatic scaling](#dedicated-instance-autoscaling) + [Automatic recovery](#dedicated-instance-recovery) + [Dedicated Spot Instances](#dedicated-instance-spot) + [Burstable performance instances](#dedicated-instance-burstable) ### Reserved Instances To reserve capacity for your Dedicated Instances, you can purchase Dedicated Reserved Instances or Capacity Reservations. For more information, see [Reserved Instances for Amazon EC2 overview](ec2-reserved-instances.md) and [Reserve compute capacity with EC2 On-Demand Capacity Reservations](ec2-capacity-reservations.md). When you purchase a Dedicated Reserved Instance, you are purchasing the capacity to launch a Dedicated Instance 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 does 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 You can use Amazon EC2 Auto Scaling to launch Dedicated Instances. For more information, see [Create a launch template using advanced settings](https://docs.aws.amazon.com/autoscaling/ec2/userguide/advanced-settings-for-your-launch-template.html) in the *Amazon EC2 Auto Scaling User Guide*. ### Automatic recovery You can configure automatic recovery for a Dedicated Instance if it becomes impaired due to an underlying hardware failure or a problem that requires AWS involvement to repair. For more information, see [Automatic instance recovery](ec2-instance-recover.md). ### 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 [Launch on single-tenant hardware](how-spot-instances-work.md#spot-instance-tenancy). ### Burstable performance instances You can leverage the benefits of running on dedicated tenancy hardware with [Burstable performance instances](burstable-performance-instances.md). 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 [Key concepts for burstable performance instances](burstable-credits-baseline-concepts.md). 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. ## Dedicated Instances limitations Keep the following in mind when using Dedicated Instances: + Some AWS services or their features are not supported with a VPC with the instance tenancy set to `dedicated`. Refer to the respective service's documentation to confirm if there are any limitations. + Some instance types can't be launched into a VPC with the instance tenancy set to `dedicated`. For more information about supported instance types, see [Amazon EC2 Dedicated Instances](https://aws.amazon.com/ec2/pricing/dedicated-instances/). + When you launch a Dedicated Instance backed by Amazon EBS, the EBS volume doesn't run on single-tenant hardware. ## Pricing for Dedicated Instances Pricing for Dedicated Instances is different from pricing for On-Demand Instances. For more information, see the [Amazon EC2 Dedicated Instances](https://aws.amazon.com/ec2/pricing/dedicated-instances/). # Launch Dedicated Instances into a VPC with default tenancy When you create a VPC, you have the option of specifying its instance tenancy. If you launch an instance into a VPC that has an instance tenancy of `dedicated`, it runs as a Dedicated Instance on hardware that's dedicated for your use. For more information about launching an instance with a tenancy of `host`, see [Launch Amazon EC2 instances on an Amazon EC2 Dedicated Host](launching-dedicated-hosts-instances.md). For more information about VPC tenancy options, see [Create a VPC](https://docs.aws.amazon.com/vpc/latest/userguide/create-vpc.html) in the *Amazon VPC User Guide*. **Requirements** + Choose a supported instance type. For more information, see [Amazon EC2 Dedicated Instances](https://aws.amazon.com/ec2/pricing/dedicated-instances/). ------ #### [ Console ] **To launch a Dedicated Instance into a default tenancy VPC** 1. Open the Amazon EC2 console at [https://console.aws.amazon.com/ec2/](https://console.aws.amazon.com/ec2/). 1. In the navigation pane, choose **Instances**, **Launch instance**. 1. In the **Application and OS Images** section, select an AMI from the list. 1. In the **Instance type** section, select the instance type to launch. 1. In the **Key pair** section, select the key pair to associate with the instance. 1. In the **Advanced details** section, for **Tenancy**, select **Dedicated**. 1. Configure the remaining instance options as needed. For more information, see [Reference for Amazon EC2 instance configuration parameters](ec2-instance-launch-parameters.md). 1. Choose **Launch instance**. ------ #### [ AWS CLI ] **To set the tenancy option for an instance during launch** Use the [run-instances](https://docs.aws.amazon.com/cli/latest/reference/ec2/run-instances.html) command and include `Tenancy` with the `--placement` option. ``` --placement Tenancy=dedicated ``` ------ #### [ PowerShell ] **To set the tenancy option for an instance during launch** Use the [New-EC2Instance](https://docs.aws.amazon.com/powershell/latest/reference/items/New-EC2Instance.html) cmdlet with the `-Placement_Tenancy` parameter. ``` -Placement_Tenancy dedicated ``` ------ # Change the tenancy of an EC2 instance You can change the tenancy of a stopped instance after launch. The changes that you make take effect the next time the instance starts. Alternatively, you can change the tenancy of your virtual private cloud (VPC). For more information, see [Change the instance tenancy of a VPC](change-tenancy-vpc.md). **Limitations** + You can't change the tenancy of an instance using the AWS Management Console. + The instance must be in the `stopped` state. + The operating system details of your instance—and whether SQL Server is installed—affect what conversions are supported. For more information about the tenancy conversion paths available to your instance, see [Tenancy conversion](https://docs.aws.amazon.com/license-manager/latest/userguide/conversion-tenancy.html) in the *License Manager User Guide*. + For T3 instances, you must launch the instance on a Dedicated Host to use a tenancy of `host`. You can't change the tenancy from `host` to `dedicated` or `default`. Attempting to make one of these unsupported tenancy changes results in an `InvalidRequest` error code. ------ #### [ AWS CLI ] **To modify the tenancy value of an instance** Use the [ modify-instance-placement](https://docs.aws.amazon.com/cli/latest/reference/ec2/modify-instance-placement.html) command. ``` aws ec2 modify-instance-placement \ --instance-id i-1234567890abcdef0 \ --tenancy dedicated ``` ------ #### [ PowerShell ] **To modify the tenancy value of an instance** Use the [ Edit-EC2InstancePlacement](https://docs.aws.amazon.com/powershell/latest/reference/items/Edit-EC2InstancePlacement.html) cmdlet. ``` Edit-EC2InstancePlacement ` -InstanceId i-1234567890abcdef0 ` -Tenancy Dedicated ``` ------ # Change the instance tenancy of a VPC You can change the instance tenancy of a virtual private cloud (VPC) from `dedicated` to `default` after you create it. Modifying the instance tenancy of a VPC does not affect the tenancy of any existing instances in the VPC. The next time that you launch an instance in the VPC, it has a tenancy of `default`, unless you specify otherwise during instance launch. Alternatively, you can change the tenancy of specific instances. For more information, see [Change the tenancy of an EC2 instance](dedicated-change-tenancy.md). **Limitations** + You can't change the instance tenancy of a VPC from `default` to `dedicated` after it is created. + You can't modify the instance tenancy of a VPC using the AWS Management Console. ------ #### [ AWS CLI ] **To modify the instance tenancy attribute of a VPC** Use the [modify-vpc-tenancy](https://docs.aws.amazon.com/cli/latest/reference/ec2/modify-vpc-tenancy.html) command. The only supported tenancy value is `default`. ``` aws ec2 modify-vpc-tenancy \ --vpc-id vpc-1234567890abcdef0 \ --instance-tenancy default ``` ------ #### [ PowerShell ] **To modify the instance tenancy attribute of a VPC** Use the [Edit-EC2VpcTenancy](https://docs.aws.amazon.com/powershell/latest/reference/items/Edit-EC2VpcTenancy.html) cmdlet. The only supported tenancy value is `Default`. ``` Edit-EC2VpcTenancy ` -VpcId vpc-1234567890abcdef0 ` -InstanceTenancy Default ``` ------