Amazon EC2 Dedicated Hosts

An Amazon EC2 Dedicated Host is a physical server that is fully dedicated for your use. You can optionally choose to share the instance capacity with other AWS accounts. For more information, see Cross-account Amazon EC2 Dedicated Host sharing.

Dedicated Hosts provide visibility and control over instance placement and they support host affinity. This means that you can launch and run instances on specific hosts, and you can ensure that instances run only on specific hosts. For more information, see Amazon EC2 Dedicated Host auto-placement and host affinity.

Dedicated Hosts provide comprehensive Bring Your Own License (BYOL) support. They allow you to use your existing per-socket, per-core, or per-VM software licenses, including Windows Server, SQL Server, SUSE Linux Enterprise Server, Red Hat Enterprise Linux, or other software licenses that are bound to VMs, sockets, or physical cores, subject to your license terms.

If you require your instances to run on dedicated hardware, but you do not need visibility or control over instance placement, and you do not need to use per-socket or per-core software licenses, you can consider using Dedicated Instances 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.	Supported
Bring Your Own License (BYOL)	Supported	Partial support *
Capacity Reservations	Not supported	Supported

* 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 about Dedicated Instances, see Amazon EC2 Dedicated Instances.

Dedicated Hosts restrictions

Before you allocate Dedicated Hosts, take note of the following limitations and restrictions:

• To run RHEL and SUSE Linux on Dedicated Hosts, you must bring your own AMIs. You can't use the RHEL and SUSE Linux AMIs that are offered by AWS or that are available on AWS Marketplace with Dedicated Hosts. For more information about how to create your own AMI, see Bring your own software licenses to Amazon EC2 Dedicated Hosts.

  This restriction does not apply to hosts allocated for high memory instances (u-6tb1.metal, u-9tb1.metal, u-12tb1.metal, u-18tb1.metal, and u-24tb1.metal). RHEL and SUSE Linux AMIs that are offered by AWS or that are available on AWS Marketplace can be used with these hosts.

• There is a limit on the number of running Dedicated Hosts per instance family per AWS account per Region. Quotas apply to running instances only. If your instance is pending, stopping, or stopped, it does not count towards your quota. To view the quotas for your account, or to request a quota increase, use the Service Quotas console.

• The instances that run on a Dedicated Host can only be launched in a VPC.

• Auto Scaling groups are supported when using a launch template that specifies a host resource group. For more information, see Create a launch template using advanced settings in the Amazon EC2 Auto Scaling User Guide.

• Amazon RDS instances are not supported.

• The AWS Free Usage tier is not available for Dedicated Hosts.

• Instance placement control refers to managing instance launches onto Dedicated Hosts. You cannot launch Dedicated Hosts into placement groups.

• If you allocate a host for a virtualized instance type, you can't modify the instance type to a .metal instance type after the host is allocated. For example, if you allocate a host for the m5.large instance type, you can't modify the instance type to m5.metal.

  Similarly, if you allocate a host for a .metal instance type, you can't modify the instance type to a virtualized instance type after the host is allocated. For example, if you allocate a host for the m5.metal instance type, you can't modify the instance type to m5.large.

Contents

• Pricing and billing
• Instance capacity configurations
• Burstable instances on Dedicated Hosts
• Bring your own licenses
• Auto-placement and affinity
• Allocate a Dedicated Host
• Launch instances on a Dedicated Host
• Launch instances into a host resource group
• Modify Dedicated Host auto-placement
• Modify supported instance types
• Modify tenancy and affinity for an instance
• Release Dedicated Host
• Migrate to Nitro-based Amazon EC2 Dedicated Hosts
• Purchase a Dedicated Host Reservation
• Cross-account sharing
• Dedicated Hosts on Outposts
• Host recovery
• Host maintenance
• Monitor Dedicated Hosts
• Track configuration changes

Purchase Dedicated Host Reservations for Dedicated Host billing discounts

Dedicated Host Reservations provide you with a discount of up to 70 percent compared to On-Demand Dedicated Host pricing. You must have active Dedicated Hosts allocated in your account before you can purchase Dedicated Host Reservations. For more information, see Dedicated Host Reservations.

You can purchase Dedicated Host Reservations using the following methods:

Console

To purchase reservations

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

2. Choose Dedicated Hosts, Dedicated Host Reservations, Purchase Dedicated Host Reservation.

3. On the Find offerings screen, do the following:

   1. For Instance family, select the instance family of the Dedicated Host for which to purchase the Dedicated Host Reservation.

   2. For Payment option, select and configure your preferred payment option.

4. Choose Next.

5. Select the Dedicated Hosts with which to associate the Dedicated Host Reservation, and then choose Next.

6. (Optional) Assign tags to the Dedicated Host Reservation.

7. Review your order and choose Purchase.

AWS CLI

To purchase reservations

1. Use the describe-host-reservation-offerings command to list the available offerings that match your needs. The following example lists the offerings that support instances in the m4 instance family and have a one-year term.

   Note

   The term is specified in seconds. A one-year term includes 31,536,000 seconds, and a three-year term includes 94,608,000 seconds.

   aws ec2 describe-host-reservation-offerings --filter Name=instance-family,Values=m4 --max-duration 31536000

   The command returns a list of offerings that match your criteria. Note the offeringId of the offering to purchase.

2. Use the purchase-host-reservation command to purchase the offering and provide the offeringId noted in the previous step. The following example purchases the specified reservation and associates it with a specific Dedicated Host that is already allocated in the AWS account, and it applies a tag with a key of purpose and a value of production.

   aws ec2 purchase-host-reservation --offering-id hro-03f707bf363b6b324 --host-id-set h-013abcd2a00cbd123 --tag-specifications 'ResourceType=host-reservation,Tags={Key=purpose,Value=production}'

PowerShell

To purchase reservations

1. Use the Get-EC2HostReservationOffering AWS Tools for Windows PowerShell command to list the available offerings that match your needs. The following examples list the offerings that support instances in the m4 instance family and have a one-year term.

   Note

   The term is specified in seconds. A one-year term includes 31,536,000 seconds, and a three-year term includes 94,608,000 seconds.

   PS C:\> $filter = @{Name="instance-family"; Value="m4"}

   PS C:\> Get-EC2HostReservationOffering -filter $filter -MaxDuration 31536000

   The command returns a list of offerings that match your criteria. Note the offeringId of the offering to purchase.

2. Use the New-EC2HostReservation AWS Tools for Windows PowerShell command to purchase the offering and provide the offeringId noted in the previous step. The following example purchases the specified reservation and associates it with a specific Dedicated Host that is already allocated in the AWS account.

   PS C:\> New-EC2HostReservation -OfferingId hro-03f707bf363b6b324 -HostIdSet h-013abcd2a00cbd123