Terminology: - Base Stack, Your primary SilverStripe Platform environment. - Virtual Stack, a secondary environment sharing the same resources as the Base Stack.

A Virtual Stack, or “vstack”, can be used to host multiple sites on one SilverStripe Platform Stack. Please consider the size and performance of your stack before adding a vstack as this will share the same server resources as the Base Stack.

Adding a Virtual Stack to your Base Stack

Virtual Stacks can be created by a Stack Manager, after an initial deployment has been made to all environments on the Base Stack, by clicking on the Virtual Stacks tab on the stack overview page.

Virtual Stack Tab
If there are existing Virtual Stacks they will be shown on this page, or you can click “Create Virtual Stack” to make a new one. Fill out the details and click “Add stack” to get started.
Virtual Stack Creation Page
Once the Virtual Stack is created, the Base Environment will require a full deployment before you can deploy to the Virtual Stack.

.platform.yml and full deployments

Virtual Stacks do not require a .platform.yml file, they use the same configuration as the Base Stack’s .platform.yml file. If a .platform.yml file is included in a Virtual Stack’s code base it will not take effect.

A Virtual Stack can not be full deployed to. To apply configuration changes such as whitelists, new domains or variables you will need to make this change on your Virtual Stack in the Platform UI and then full deploy to the Base Stack.