Migration Openstack: QEMU image to Ceph RBD
The other day I needed to migrate a bunch of Openstack VMs (~1T of volumes) from openstack version ‘Stein’ to a brand new ‘Caracal’ platform. The former was using NFS based storage. The latter Ceph, obviously. Glance storage is still NFS mounted. So let’s try to migrate this the ‘Openstack way’. Turns out Openstack (Cinder) needed to copy the data 3 times! Download from glance to some temporary storage Convert the image to ‘raw’ format, even if the uploaded image is already ‘raw’....