I recently had to upload an image on a 4.4.0-31 engine and Nir told me to share here the feedback.

I installed ovirt-imageio-common-2.0.5-0.el8ev.x86_64

and created the following script to upload it using sdk:

#!/usr/bin/bash

python3 /root/ovirt-engine-sdk/sdk/examples/upload_disk.py \
    --engine-url "https://`hostname`/" \
    --username admin@internal \
    --password-file pssword  \
    --cafile /tmp/ca.pem \
    --disk-format qcow2 \
    --disk-sparse \
    --sd-name nfs_0 \
    /tmp/rhel-guest-image-7.6-210.x86_64.qcow2

The image got uploaded pretty quickly and I didn't have any trouble...

Cheers,

Gui