(1) Do a blockdev-add:

QMP> {
    "execute": "blockdev-backup", 
    "arguments": {
        "device": "drive-ide0-0-0", 
        "target": "/home/kashyapc/tinker-space/qemu-upstream/scripts/qmp/backup1.qcow2", 
        "sync": "full"
    }
}


(2) Perform 'blockdev-backup' to the target

$ socat UNIX:/export/qemu-backup-tests/qmp-sock READLINE,history=$HOME/.qmp_history,prompt='QMP> '
{"QMP": {"version": {"qemu": {"micro": 0, "minor": 6, "major": 2}, "package": " (qemu-2.6.0-3.fc24)"}, "capabilities": []}}
QMP> {"execute":"qmp_capabilities"}
{"return": {}}

QMP> 
{   "execute": "blockdev-backup", 
    "arguments": {
        "device": "drive-ide0-0-0", 
        "target": "drive-ide2-0-0", 
        "sync": "full"
    }
}


(3) Result:

QMP> {"execute":"qmp_capabilities"}
{"return": {}}
QMP> {   "execute": "blockdev-backup", 
QMP>     "arguments": {
QMP>         "device": "drive-ide0-0-0", 
QMP>         "target": "drive-ide2-0-0", 
QMP>         "sync": "full"
QMP>     }
QMP> }
{"return": {}}
{"timestamp": {"seconds": 1466158164, "microseconds": 695444}, "event": "BLOCK_JOB_COMPLETED", "data": {"device": "drive-ide0-0-0", "len": 41126400, "offset": 41126400, "speed": 0, "type": "backup"}}
QMP>