digraph techviz {
  graph [rankdir=LR, splines=ortho, nodesep=0.55, ranksep=0.85];
  node [fontname=Helvetica, fontsize=11, margin="0.18,0.12", style="rounded,filled", fillcolor=white, color="#2d4357", penwidth=1.5];
  edge [fontname=Helvetica, fontsize=10, color="#364b5f", penwidth=1.4, arrowsize=0.75];
  n0 [label="/dev/vda", shape=cylinder, style="rounded,filled"];
  n1 [label="virtio-blk · virtqueue", shape=box, style="rounded,filled"];
  n2 [label="QEMU block backend", shape=box, style="rounded,filled"];
  n3 [label="qcow2 file", shape=cylinder, style="rounded,filled"];
  n4 [label="RAW file", shape=cylinder, style="rounded,filled"];
  n5 [label="Host block device", shape=cylinder, style="rounded,filled"];
  n0 -> n1 [label="block I/O", style=solid];
  n1 -> n2 [label="VM boundary", style=solid];
  n2 -> n3 [label="qcow2 backend", style=solid];
  n2 -> n4 [label="RAW backend", style=solid];
  n2 -> n5 [label="block-device backend", style=solid];
}