Templates are crucial components in the Gallium ecosystem that streamline the deployment of Virtual Machines (VMs). A template comprises several settings that determine the characteristics of the VMs created from it. Templates are provided by Gallium for a number of popular Operating Systems or can be created manually.
Template Settings
Name: This is the short name for the template, serving as an identifier for your template.
Description: Here, you can provide a detailed description of the template. It's useful for mentioning any customisations or scripts that may run when the VM created from this template is deployed.
OS Type: The OS Type determines the operating system that the VMs created from the template will run. The options include Linux, Windows, or Other.
Linux: VMs based on Linux will require the VirtIO Storage and Network drivers. These are included in nearly all modern Linux distributions, so no further action is necessary.
Windows: VMs based on Windows will also require the VirtIO Storage and Network drivers. However, these drivers aren't included in Windows by default and need to be added manually to the template.
Other: This option uses a SATA device driver and E1000 network adapter, maximizing compatibility with a wide variety of operating systems. While the Other option may result in some performance loss, it ensures the broadest possible compatibility.
Minimum Memory: This setting denotes the smallest amount of memory that the VM created from the template can use.
Disks: Disk images for the template are uploaded in either QCOW2 or ISO format. A maximum of 6 disks can be added to a Template.
Uploaded Disks are stored in the Cloud. Every time a VM is deployed, the Hypervisor checks its local cache for a copy of the disk image before downloading it. Uploaded Disks can be expanded at Virtual Machine creation time.
Blank Disks are empty disks which are created and expanded on each Virtual Machine deployment.
Uploaded ISOs are optical media that will be mounted to the Virtual Machine at boot. This is useful for deploying operating systems where a Cloud-Ready image isn't available.
Template Setup Process
Creating a template in Gallium involves the following steps:
Create Draft: Initiate the process by creating a draft of your template from
Inventory > Templates > Create New Template. During this step, you can define the appropriate OS and Memory settings.Configure Disks: Upload the disk images in the appropriate format (QCOW2 or ISO). These disk images serve as the base for the storage of the VMs created from the template.
Finalise: Once the disk images are uploaded and the settings are appropriately defined, you can finalize the template. Once a template is finalized, it's ready to be used for deploying VMs and can no longer be modified.