sudo ionice -c 3 rsync -n -av \
  -e "ssh -c arcfour -l nicolaw -i /home/nicolaw/.ssh/id_rsa" \
  --protocol=29 \
  --remove-source-files \
  --delete-after \
  --size-only \
  --progress \
  --rsync-path="sudo ionice -c 3 rsync" \
  host:/src/path /dest/path