Some virtual machine configurations that you may be using in your on-premises data center are not supported in the SDDC. Others are supported with limitations.

Use vSphere Virtual Machine Administration in the VMware vSphere Documentation as your guide to creating, configuring, and managing workload VMs in VMware Cloud on AWS. Because VMware Cloud on AWS is a service, some VM configuration options documented in vSphere Virtual Machine Administration aren't available for use in an SDDC even though they may be mentioned in a help topic or listed in the vSphere Client when you right-click a workload VM and choose Edit Settings. But with a few exceptions, which we document here, you can use the guidance provided in that document when you configure, deploy, and manage workload VMs in the SDDC.

For other limits imposed by VMware Cloud on AWS, see VMware Configuration Maximums.

Table 1. On-Premises VM Configuration Options That Are Unavailable in an SDDC
Configuration Option References Comments
Use the vSphere Client and the vSphere Web Client. The vSphere Client and other topics. Only the vSphere Client is supported for access to the SDDC vCenter.
Enable hyperthreading in a virtual CPU. Virtual CPU Configuration and other topics. To mitigate security vulnerabilities, including the ones discussed in VMware Knowledge Base article 55806 and VMware Knowledge Base article 55808, VMware Cloud on AWS manages CPU hyperthreading on all hosts.
Change CPU identification masks. Change CPU Identification Mask Settings You cannot change CPU ID mask of a VM in your SDDC.
Change virtual disk type. Change the Virtual Disk Configuration You cannot change storage type for virtual disks on a VM in your SDDC.
Configure virtual hardware. Virtual Machine Hardware Available to vSphere Virtual Machines You cannot create a VM that includes any virtual hardware device that requires a physical change to the host. This includes things like serial ports, USB drives, and floppy drives.
Add a SCSI controller. Add a SCSI Controller to a Virtual Machine You can add a SCSI controller but cannot use virtual SCSI bus sharing.
Map a raw LUN or logical disk. Raw Device Mapping VMware Cloud on AWS does not support external block storage. You cannot deploy a VM that uses an RDM disk in an SDDC.
Add a hard disk. Large Capacity Virtual Disk Conditions and Limitations VMware Cloud on AWS does not support external block storage. You cannot deploy a VM that uses VMFS5 or NFS in an SDDC.
Add a network adapter Network Adapter Basics VMware Cloud on AWS supports only E1000E, VMXNET3, and SR-IOV adapters.
Add virtual CPUs Virtual CPU Limitations Because hyperthreading is disabled in VMware Cloud on AWS hosts, a virtual machine in the SDDC cannot have more virtual CPUs than the number of physical cores on the host.
Configure a PCI passthrough device Configure a PCI Device on a Virtual Machine This feature is not supported in VMware Cloud on AWS
Encrypted VMs Virtual Machine Encryption This feature is not supported in VMware Cloud on AWS

On-Premises VM Configurations that are Blocked or Limited in an SDDC

Certain VM configuration options can prevent the host from entering maintenance mode, interfere with vMotion, or otherwise prevent VMware from performing service upgrades. These configurations, which are permitted on premises, have limited support or no support the SDDC. If you upload a template with an unsupported configuration from your on-premises content library to your SDDC, VMs created from the template will not power on in the SDDC.

Table 2. VM Configurations With Limited or No Support in the SDDC
Configuration Option Support Comments
VM includes a serial port with network output None This configuration is blocked in the SDDC
VM disk enables both multi-writer and Changed Block Tracking (CBT) None This configuration is blocked in the SDDC.
VM includes a parallel port None Parallel ports are not supported for physical device or file output.
VM uses virtual or physical bus sharing Limited Physical bus sharing configurations are supported on hardware version 11 and later.
VM mounts a VMware Tools ISO and initiates a tools installation or upgrade. Limited vMotion is not allowed during VMware tools installation or upgrade. If vMotion required by SDDC maintenance is blocked by VM in this state, the system allows a few minutes for the operation to complete. If the operation does not complete, the system terminates the upgrade or installation and unmounts the ISO image to unblock the maintenance event. You'll need to manually re-start the installation or upgrade process after the maintenance is complete.