echo "Creating new backing file"
echo
_make_test_img 1G
io_pattern writev 0 $((2 * CLUSTER_SIZE)) $((4 * CLUSTER_SIZE)) 4 0x22
echo "Creating new backing file"
echo
_make_test_img 1G
io_pattern writev 0 $((2 * CLUSTER_SIZE)) $((4 * CLUSTER_SIZE)) 4 0x22