ConVirt allows administrators to define their images and create Virtual Machine configurations from them. For example, in a particular data center, four types of machines are to be provisioned frequently. They are Red hat, CentOS, Suse and Ubuntu. You can configure ConVirt to point to kernel and ramdisk of each of these distributions and install/deploy many virtual machines using predefined images. The collection of images are referred to as an Image Store.
ConVirt ships with a default image store containing a few useful provisionable images. One can either edit them in place or use the new "Create Like" feature to create an image that is similar to one of the existing images.
The image store also allows you to organize your images in to various image groups. One can drag and drop the image to move it from one group to another.
Sophisticated users may also construct their own, arbitrarily complex image descriptions and provisioning schemes and add them to the Image Store. For instructions on how to build custom provisionable images, please consult the Image Builders Guide
The Image Store is listed in the navigator. Clicking or expanding the Image Store node results in a listing of the available, provisionable images. Right click on the Image Store presents a menu with "Import Appliance" see the next section for details on appliance management.
- Click selects the image and displays useful information about it in on the right hand side. This information typically included a brief description of the provisionable image, pre-requisites and deployment instructions. So, read this information carefully before attempting to provision the image.
- Right Click brings up a context menu with various image specific tasks. These are:
- Provision. Start the provisioning process. Launches a dialog prompting for the managed server to target for provisioning.
- Edit Settings Alter the definition of the image. Any changes made here are permanent and apply to all subsequent VM's provisioned using this image. (more detail below)
- Edit Script (Advanced Feature). Alter the mechanism used to provision VM's using this image. This is an advanced feature and should be left alone unless you are designing your own provisionable image.
- Edit Description (Advanced Feature). Edit the description associated with this image. This is the description that appears on the right hand side once the user left-clicks on an image name in the navigator. Unless you are designing your own provisionable image, leave this alone.
- Create Like (Advanced Feature). Creates a copy of the selected image. This is particularly useful in creating customized images to suit a particular data center needs.
- Delete. Deletes the selected image from the library. CAUTION : All the content related to the image would be lost permenantly.
- Edit Settings Dialog This is a multi-purpose, context sensitive dialog that can be launched to manipulate settings for provisionable images or existing VM configurations. When launched in context of an image, this dialog presents two top-level tabs, each affecting a different aspect of the provisioning process:
- Virtual Machine This tab controls the various parameters and settings controlling the configuration* of the VM's provisioned with this image. In typical usage, user will likely not make any changes here, save for perhaps changing disk settings to better match the deployment environment.
- Provisioning This tab controls the various parameters and settings controlling the mechanism by which VM's are provisioned using the selected image. A typical alteration here would be to change the disk size and type parameters governing the default sizes and types (VBD/LVM) of system disks created during provisioning process. A detailed description of the configuration/mechanism distinction and how parameters may be shared between the two is an advanced topic, more fully addressed in the Image Builders Guide
Out of the box the images supplied would work with default values. You might want to do some initial setup to suite to your environment. There are few options in the provisioning area that are worth mentioning. It is recommended that you set these values on a per server pool using the Server Pool Settings option.
- VM_DISKS_DIR : Location where disks for newly created VMs would be placed. Default /var/cache/convirt/vm_disks.
- VM_CONF_DIR : Directory where the VM config files would be placed. Default /var/cachec/convirt/vm_configs.
- http_proxy : Proxy to be used while provisioning. Default to no proxy (blank). The format for the
proxy is http://myproxyserver:myproxyport
- cd rom location : Another thing you might want to customize is to make sure that the device for the cdrom is correct for images that install from a CDROM. It is usually /dev/cdrom, but it might be different on your machine. You can make this change in the disk area under the general tab.
The image store also contains a _template_ image. This is a skeleton for an image and can not be provisioned directly. One should populate the template with suitable values and then use create like from the template to create one or multiple images. This particular template is encouraging shared area for the vm disks, one of the primary requirements for migration.