{"execute": "blockdev-add", "arguments": {"driver": "null-co", "node-name": "disk", "size": 1048576}}
{"return": {}}
{"execute": "block-dirty-bitmap-add", "arguments": {"name": "bitmap0", "node": "disk"}}
{"return": {}}
{"execute": "nbd-server-start", "arguments": {"addr": {"data": {"path": "SOCK_DIR/PID-nbd.sock"}, "type": "unix"}}}
{"return": {}}
{"execute": "nbd-server-add", "arguments": {"bitmap": "bitmap0", "device": "disk", "writable": true}}
{"return": {}}
read 512/512 bytes at offset 0
512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)