Chapter 4. Converting virtual machines to run on Red Hat Enterprise Virtualization

It is important to note that when converting a guest virtual machine to run on Red Hat Enterprise Virtualization, not all combinations of storage format and allocation policy are supported. The supported combinations differ according to whether the Red Hat Enterprise Virtualization data center the guest will be imported into uses block (FC or iSCSI) or file (NFS) for its data storage domain. Note that virt-v2v writes to an export storage domain, and this is always required to be NFS.

Data format and allocation policy of the virtual machine being converted by virt-v2v will be preserved unless the output data format and allocation policy are specified using the -of and -oa parameters respectively. To import virtual machines using sparse allocation into an FC or iSCSI data center, the storage format must be converted to qcow2. This is achieved by passing the parameters -of qcow2 -oa sparse to virt-v2v. Note that converting between raw and qcow2 formats is a resource intensive operation, and roughly doubles the length of time taken for the conversion process.