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Amazon EC2 Dedicated Hosts FAQs

Q: What is a Dedicated Host?

An Amazon EC2 Dedicated Host ("Dedicated Host" or "host") is a physical server with EC2 instance capacity fully dedicated to your use.

Q: What are the benefits of using Dedicated Hosts?

Dedicated Hosts can save you money by enabling you to leverage your existing server-bound software license investments (e.g., Windows Server, Windows SQL Server, and SUSE Linux Enterprise Server) within EC2, subject to your license terms. Dedicated Hosts also give you more flexibility, visibility, and control over the placement of instances on dedicated hardware. This makes it easier to ensure you deploy your instances in a way that meets your compliance and regulatory requirements.

Q: Is a Dedicated Host a baremetal offering?

No, the instances that run on a Dedicated Host are the same virtualized instances that you’d get with traditional EC2 instances that use the Xen hypervisor.

Q: What is the lifecycle of a host?

A host becomes accessible after you have allocated it within your account. After you allocate a host the instance capacity will be standing by for your use. You can then launch instances with a tenancy of "host" using the RunInstances API or the Amazon Web Services Management Console. When you no longer need to use a host, if it is an On-Demand Dedicated Host, you first need to stop or terminate all of the instances running on the host, and then you can release the host using the ReleaseHosts API or the Amazon Web Services Management Console.

When Reservations are available, you can purchase a Reservation and assign it to a host after that host has been allocated to your account. If your host is covered by a Reservation, the Reservation first needs to expire before you can release the host.

Q: What are the general steps that I need to follow to bring my own licenses (BYOL) into EC2?

  1. Verify the licensing terms controlling your use of your BYOL software within EC2. We recommend that you consult with your own advisors to understand whether you comply with the applicable licensing requirements.
  2. Once you have verified that your licenses can be used within EC2, import your machine images using the ImportImage API made available by the VM Import/Export service. Alternatively, you may be able to download the software directly to the instance (e.g., Oracle).
  3. If you need a mechanism to track your images in Amazon Web Services, enable host and instance recording in the Amazon Web Services Config service.
  4. After you’ve imported your image, you can launch instances from these images onto Dedicated Hosts.
    Note that when you run these instances, you may be required to activate these instances against your own KMS server (e.g., Windows Server, Windows SQL Server).
Q. Can I use my existing Windows Server license with EC2?
 
You can bring your own Windows Server licenses to Amazon EC2 Dedicated Hosts in Amazon Web Services China (Ningxia) region, operated by NWCD and Amazon Web Services China (Beijing) Region, operated by SINNET. We encourage you to work with your Microsoft account representative to understand licensing options.
 
Q. What software licenses can I bring to the Windows environment?
 
Specific software license terms vary from vendor to vendor. Therefore, we recommend that you check the licensing terms of your software vendor to determine if your existing licenses are authorized for use in Amazon EC2.
 
Q: What purchasing options do I have for paying for a host?
 
Dedicated Hosts can be purchased On-Demand (hourly). Reservations can provide up to a 78% discount compared to the On-Demand price.
 
Q: How am I billed for a host that is running On-Demand?
 
You will pay the On-Demand rate for every hour the host is active in your account, regardless of the number of instances, or types of AMIs, that are running on the host.
 
Q: Do I need to specify a tenancy when I want to launch an instance on a host?
 
Yes, you need to specify a tenancy of "host" when you want to launch instances onto a host.
 
Q: What is the tenancy for instances that run on hosts?
 
The tenancy for the instances running on a host is "host".
 
Q: Can I launch instances on a specific host?
 
Yes, you can launch instances on a specific host using the host ID as a target in the Amazon Web Services Management Console or the RunInstances API.
 
Q: Can I have instances with different sizes on the same host?
 
No, when you allocate a host, the instance size configuration will be uniform across the entire host.
 
Q: Can I mix multiple EC2 instance types on a single Dedicated Host?
 
A: Yes. Dedicated Hosts powered by the Amazon Web Services Nitro System support multiple instance types within the same instance family on a single host. For example, you can run r5.2xlarge and r5.4xlarge instances on the same host. See the Dedicated Host Pricing Page for more detail.

Q: How do I know how many instances I can run on each host?
 
The maximum number of instances you can run per host varies based on the instance type configuration you select. You can see the maximum number of instances per host on the Dedicated Host Configuration Page or in the EC2 Dedicated Host console or the DescribeHosts API.  
 
Q: What AMIs can be launched onto hosts?
 
You can use BYOL, Amazon Linux, Windows Server AMIs provided by Amazon, and Amazon Web Services Marketplace AMIs on Dedicated Hosts.
 
For more details on Windows Server AMIs on Dedicated Hosts, refer to the Dedicated Hosts pricing section.

Q: Can I run an instance on a host with the EC2 Classic network type?
 
No, the instances that run on hosts can only be assigned to an Amazon VPC.
 
Q: Can I change the tenancy of my Dedicated instances from "dedicated" to "host"?
 
Yes, after you’ve stopped your Dedicated instances, you can change the tenancy to "host" using the ModifyInstancePlacement API or the Amazon Web Services Management Console.
 
Q: Do I need to create new VPCs if I migrate Dedicated instances in a Dedicated VPC to "host" tenancy?
 
No, both Dedicated instances and instances running on hosts can be assigned to a Dedicated VPC.

Q: Is there a limit that governs how many hosts I can allocate to my account?

Yes. For more information, visit documentation on Amazon Web Services Service Limits.

Q. Should I Consider a Dedicated Host Reservation a Capital or Operational Expense?

Whether you are measured on EBITDA performance or not, you may need to understand the definition of a product before you can make an operational expense (OPEX) vs capital expense (CAPEX) classification for Dedicated Host payments. The following FAQ is helpful if you need to reach an OPEX vs CAPEX conclusion on a Dedicated Host reservation.

Q: Should I consider a purchase of a Dedicated Host Reservation as CAPEX or OPEX?

Amazon Web Services does not provide accounting advice and we recommend that you ask your accountant to answer this question. We also recommend that your accountant review the definition of the EC2 Dedicated Host and a Dedicated Host Reservation before making an operational expense vs. capital expense judgment.

Q: Can I uniquely identify a Dedicated Host?

Yes, you can identify each Dedicated Host while it is allocated to your account using the Host-ID.

Q: Is the Host-ID similar to an asset-ID of a physical server?

Yes, a Host-ID is similar to an asset-ID of a physical server because a Dedicated Host can be used and identified through the use of the Host-ID. There is a one-to-one relationship between a Host-ID and a physical server while the Dedicated Host is allocated to your account.

Q: Can I release a Dedicated Host?

Yes, but only if the Dedicated Host is considered an On-Demand Dedicated Host. When a Dedicated Host is released, On-Demand billing will terminate and you will not be able to reuse the previously allocated Dedicated Host (or Host-ID).

Q: Will Amazon Web Services reuse the same Host-ID for different physical servers?

No, Amazon Web Services will not swap physical servers from under the Host-ID. If you get a new physical server, you will also get a new Host-ID.

Q: Can I reuse the same Dedicated Host over time?

Yes, as long as your Dedicated Host hasn’t been released, you can also reuse the same Dedicated Host over time.

Q: How am I billed for a Dedicated Host?

You pay for the entire Dedicated Host by the hour, regardless of how many instances are running on the Dedicated Host. If there are additional charges as a result of use, such as networking or software charges, they will be separated in different line items on the bill.

Q: What payment options do I have for Dedicated Hosts?

You have two payment options. The first is On-Demand, where you have the flexibility to scale up and down the number of Dedicated Hosts allocated to your account and only pay for the hours those Dedicated Hosts were allocated to your account. The second option is by Reservation, where you can purchase and assign a Reservation to a Dedicated Host and benefit from a lower rate over the term compared to On-Demand. Reservations can save you up to 70% on your On-Demand costs over the term.

Q: What are the payment options for a Reservation?

You can choose an All Upfront Reservation, where you roll all of the cost of your Dedicated Host reservation into one upfront payment. The All Upfront Reservation provides the best overall price compared to the Partial Upfront and No Upfront offerings. With the Partial Upfront payment option, you pay for roughly half of the cost of the Reservation upfront and the remaining cost is amortized (and charged hourly) across each hour in the term. The Partial Upfront payment option provides a better price than the No Upfront payment option. With the No Upfront payment option you pay nothing upfront and the entire cost of the Reservation is amortized (and charged hourly) across each hour in the term.

Q: Can I obtain a Reservation for a Dedicated Host?

Yes, after you’ve allocated a Dedicated Host to your account, you can pay for a 1 or 3 year Reservation for it. When you purchase a Reservation and assign it to the Dedicated Host, you are committing to pay for that Dedicated Host for a minimum period of time equal to the term of the Reservation.

Q: Can I pay for a Reservation without having it assigned to a Dedicated Host?

No, Reservations need to be assigned to Dedicated Hosts that have been allocated to your account.

Q: Do I maintain remote control over the use of a Dedicated Host when the Reservation expires?

Yes, when your Reservation expires, your Dedicated Host will remain allocated to your account and you can continue to use the Dedicated Host. When the Reservation expires you will be billed On-Demand unless you decide to release it. You can optionally pay for another reservation for the same Dedicated Host if you wish.