CloudStack provides administrators a good control to manage the guest operating systems for the Instances. CloudStack maintains the list of guest operating systems that are supported by the hypervisors and also provides a way for operators or admins to add new guest OSs based on the need. For an operating system to be supported to CloudStack for the Instances, it has to be added in CloudStack and also need to have a mapping with the actual operating system name supported by hypervisor.
Under "Configuration" section there are sub-sections for guest operating system.
A list of existing categories for the guest operating systems are shown as "Guest OS Categories" section. Operators can also add new guest operating system categories from the view.
Guest operating system categories are useful for categorizing images, i.e., templates and ISOs, in several UI forms such as deploying an instance, reinstalling an instance, etc., when the modern image selection is used in the UI configuration.
To allow a guest operating system category to be displayed in the UI forms, it must be marked as featured. The order of the categories can also be controlled using the Order option in the categories view.
Like other resources, a custom resource icon can be set for a particular guest operating system category for further control. If no resource icon is set for a category, the UI will display default icons based on the category name.
An existing guest OS category can be deleted if it does not have any associated guest operating systems.
The "Add guest OS category" option allows operators to create new categories, which can be marked as featured if they are meant to be displayed in the UI forms.
A list of supported guest operating systems are shown under 
and also one can add new operating systems.
To add a new guest OS, click on the button 
and following details needs to be provided:
- OS name : Name of the operating system which will be displayed to the users.
- OS category : Category of the operating system to which it belongs, eg. Windows, CentOS, Debian, etc.
Operator also need to add mapping with the actual operating system name supported by hypervisor as below.
Existing mappings are shown here and also one can add new mapping to an operating system.
To view the mappings of an existing guest OS click on 
under guest OS details.
To a new mapping, inside the sub-section 
click on 
and following details needs to be provided.
- OS type : Select the operating system type to which mapping needs to be created.
- Hypervisor : Name of the hypervisor.
- Hypervisor version : Specific version of the hypervisor. The exact version number found from hypervisor capabilities list.
- Hypervisor mapping name : Name of the operating system specific to the hypervisor. Eg. For CentOS 5.0 (64-bit) in VMware
- the specific name is "centos64Guest".
- Check OS name with hypervisor : A toggle button to specify whether to verify the hypervisor mapping name with available
- hypervisor.
- Force : A toggle button to force add a user defined guest os mapping, overrides any existing user defined mapping.
Operator can also do operations like edit and delete guest OS and its hypervisor mappings.