We are migrating all our storages to a new rack. The running instances we could all migrate to the new storages. Now we need to migrate the image store and we are wondering if we can just take it offline for an hour and move it into the new rack. Or do we have to sort of live migrate them as well?
To migrate images from one datastore to another, you can clone the images by selecting the new datastore as the destination. Once cloned, you can delete your old datastore from OpenNebula. Note that this will generate images with new IDs, so you will have to update the templates of your virtual machines in case you use any of the old images in any VM template.
Thanks. But my question was going more into another direction. Is there a link between the running VMs and the images? Do the running VMs need the images (e.g. because of snapshot deltas or similar). Or can I just shut down the image storage for a while and all VMs are running fine?
Thanks for the explanation! No, the images from the IMAGE datastore aren’t linked to the disks contained in the SYSTEM datastore as the SYSTEM datastore disks are just copies of the IMAGE datastore images as long as you don’t use persistent disks in your VMs (In this case you cannot delete an image if it’s marked as persistent and is being used by some VM).
Thanks for the answer. This helps me to plan the migration.