Disk Image Pipelines

Richard W.M. Jones (rjones @ redhat.com)
Monday February 15th, 2021

Virt-v2v is a project for lifting and shifting workloads from VMware to open source management platforms like oVirt/RHV, OpenStack and KubeVirt. To do this we have to copy vast amounts of data quickly, modifying it in flight. Nearly everything we have to copy is a virtual machine disk image. There are techniques you can use to copy disk images very efficiently:

• without copying zeroes or deleted data
• without making temporary copies
• without touching the originals
• and modifying the contents in flight