redirecting disk conversion from /var/tmp

We are migrating VMs from vSphere to OLVM. We have created the OVAs are able to import them using the GUI but also primarily we've been importing using the ovirt sdk.

During the import process, the disks are converted from vmdk to qcow2on the importing host. The disk conversion happens by default inside of /var/tmp.

Referencing docs like, guestfs & It is possible to change the temp folder for the virt-v2v conversion ? - Red Hat Customer Portal say that there should be valid env vars to redirect to a directory other than /var/tmp.

We've had no success so far with any of the following vars.