1. Overview
   1. Google Cloud provides the flexibility for bringing existing licenses
   2. Bringing existing licenses requires users to bring their own media and to run that media on hardware configurations, such as sole-tenant nodes, that are compliant with the licenses
   3. Before attempting to bring images with existing licenses to Google Cloud, review the licensing terms and conditions
   4. Google Cloud provides tools to help manage compliance requirements related to licenses
   5. Users can bring images with existing licenses in any region that supports sole-tenant nodes
   6. Although there is no additional charge for bringing images with existing licenses, users must still pay for licenses according to the license agreements
   7. Sole-tenant nodes are physical servers dedicated to hosting VMs
   8. Sole-tenant nodes can be configured to support workload requirements such as minimizing the number of physical servers and cores
   9. Consult licensing agreements to determine which configuration options are most suitable for the workloads
   10. There are other licensing scenarios that do not require sole-tenant nodes, for example, licenses related to Microsoft applications
2. Licensing
   1. Users can buy premium images with licenses from Compute Engine with pay-as-you-go billing on Compute Engine-managed licenses
   2. Bring your own license is available on sole tenancy
   3. Users can use existing licenses on dedicated hardware to leverage existing perpetual licenses
   4. Compute Engine supports license mobility
   5. Users can use existing licenses to deploy eligible Microsoft Windows Server applications on Compute Engine
   6. Customers, and not Google, are solely responsible for ensuring compliance with Microsoft licensing under any Bring Your Own License (BYOL) arrangement
   7. Google will provide the tools, but customers are responsible for compliance
   8. Customers may have bespoke licensing arrangements with Microsoft which result in different requirements (more or less restrictive)
   9. Google cannot make definitive claims on whether or not customers are covered
   10. To ensure Microsoft licensing compliance, customers can choose Google Cloud's premium Windows licenses, which are offered on a pay-as-you-go model
   11. Unlike premium images where Compute Engine takes care of license activation, imported BYOL images require customers to own the license activation process
   12. For sole-tenant nodes, customers are charged for the entire node + a 10% premium
   13. This reserves the entire node for use
   14. As many (or as few) VMs can be installed on the node without any additional cost
   15. Configuring the node to support BYOL will not result in additional charges
   16. Both sustained use discounts and committed use discounts apply to sole-tenant nodes
   17. License and billing behaviour are controlled by the OS option selected during the disk import process
   18. If a wrong option or Compute Engine public Images is used as a source, Google Cloud pay-as-you-go licenses are attached and there are no way to change that VM to use the customer's own licenses later
   19. The sole-tenant functionality allows nodes to be restarted in-place, in order to limit physical server usage
   20. This feature is coupled with the terminate option, which means that VMs are terminated and then restarted when a maintenance event occurs
3. Images
   1. To provision VMs with existing licenses, users must bring their own media
   2. Images based on a Google Cloud premium image are not eligible for BYOL because premium images require pay-as-you-go licenses from Google
   3. The import virtual disk tool can help import customized virtual disks, create images based on those disks, set up the appropriate license configuration, and install the packages and drivers necessary for compatibility with Google Cloud
   4. The import image workflows are customizable and available on GitHub
   5. Google supports offline image import for some operating systems
   6. In addition to importing operating system images that are offline, users can import images from VMs that are online and running
4. Configuration
   1. Depending on licensing scenarios and workloads, users might want to limit the number of physical cores used by VMs
   2. Sole-tenant nodes provide configuration options which vary based on how and whether VMs are live migrated during monthly maintenance events on the host
   3. VMs live migrate to any server: Physical core usage is not minimized during host maintenance events, and VMs are moved to a new host without regard for affinity to a certain set of servers
   4. This is the default configuration option, and is recommended for per-user or per-device licenses
   5. VMs are live migrated within a fixed pool of physical servers (sole-tenant node group) during host maintenance events
   6. Unlike the default setting where VMs live migrate to any server, with this setting, nodes in a sole-tenant node group are pinned to a fixed set of physical servers to support server-bound licenses
   7. To ensure capacity for live migration, Compute Engine automatically reserves one out of every twenty nodes (5 percent) that is provisioned
   8. This option is recommended for high-availability workloads with licenses that are based on the number of physical cores or processors
   9. With VMs restart in-place, VMs are terminated and then restarted on the same physical server during a host maintenance event, which occur approximately every 4 to 6 weeks
   10. This option is recommended for workloads that are fault-tolerant and must remain on the same physical server, or for licenses that are based on the number of physical cores or processors.
5. Maintenance
   1. Rarely, a server might experience a critical hardware failure
   2. If this happens, Compute Engine retires the physical server and its unique identifier, revokes access to the physical server, assigns a replacement node with a new unique identifier, and moves VMs onto the replacement node
   3. Depending on the configuration of sole-tenant nodes, Compute Engine might restart VMs