Managing your cloud resources with OpenStack: Difference between revisions

=Working with images= <!--T:42-->

Images are files which contain the contents of a virtual disk. Often Images contain a base operating system used to create an initial volume or ephemeral disk from which a virtual machine boots. An ephemeral disk is a virtual disk file which resides on the host (or hypervisor) where the virtual machine runs. Ephemeral disk files are destroyed when a VM is destroyed, in contrast to [[OpenStack#Working with Volumes|volumes]]. Images are portable in that they can be download from the cloud, used to create a virtual machine using virtual box or similar on your laptop, and uploaded to another cloud and used to create a new virtual machine. This is not the case with volumes or ephemeral disks. Images come in a variety of formats. Some commonly encountered formats are, raw, qcow2, vmdk, and vdi.

If sharing your virtual machine images be sure to remove sensitive information such as public/private keys, configuration files containing passwords etc. If uploading images created from a virtual box virtual machine to be used on many cloud platforms (including OpenStack) it must have cloud-init installed and configured correctly to work within the cloud (see openstack docs on [https://docs.openstack.org/image-guide/create-images-manually.html creating images mannually] for more details and examples on a few common operating systems).

For a list of images provided by staff on Compute Canada clouds see [[Cloud resources#Images| images]].

The procedure for creating an image of a VM depends on whether it is booting from a volume (typically "p" flavors), or from an ephemeral disk (typically "c" flavors).