OpenNebula

The attached qcow2+mds.tar.gz provides image/transfer drivers for qcow2 and multiple datastore. The primary purpose for these drivers was to provide qcow2 thin cloning and multiple datastore support. For our use cases the drivers work perfectly with 3.0.

These drivers change datastore pathing (see attached image). On the frontend, datastores are mounted under /srv/datastore/${GNAME} where GNAME is the same as VDC. On hosts, its assumed a host belongs to a single VDC, the specific datastore is mounted as /srv/vm.

The image driver (mds) supports both url and file based images and will place images into the appropriate datastore. Note the mkfs script has never been implemented and will simply log and exit.

The transfer manager (qcow2) thin cloning reduces VM provisioning to seconds and saves significant storage. Any 'saveas' operations converts the thin clone back to a full image before copying back into the image repository. Persistent VMs, just like the nfs/shared transfer manager, is a symlink. Portions of the driver borrow from the ssh driver.