$ sudo ndctl read-labels -j all
[
  {
    "dev":"nmem1",
    "index":[
      {
        "signature":"NAMESPACE_INDEX",
        "seq":2,
        "nslot":1016
      },
      {
        "signature":"NAMESPACE_INDEX",
        "seq":3,
        "nslot":1016
      }
    ],
    "label":[
      {
        "uuid":"359c68f7-efd9-410b-a727-1def27d574b5",
        "name":"number1",
        "slot":0,
        "position":1,
        "nlabel":4,
        "isetcookie":5125243788704424131,
        "dpa":268435456,
        "rawsize":3221225472
      },
      {
        "uuid":"c4047c15-7fa1-4f59-b60f-676f23326989",
        "name":"number2",
        "slot":1,
        "position":1,
        "nlabel":4,
        "isetcookie":5125243788704424131,
        "dpa":3489660928,
        "rawsize":3221225472
      },
      {
        "uuid":"56252c66-b1f1-435c-821a-67becef82f4c",
        "name":"number3",
        "slot":2,
        "position":1,
        "nlabel":4,
        "isetcookie":5125243788704424131,
        "dpa":6710886400,
        "rawsize":3221225472
      },
      {
        "uuid":"5b6e072c-5abb-43ff-ba8a-3bca6ee19068",
        "name":"number3",
        "slot":3,
        "position":1,
        "nlabel":4,
        "isetcookie":5125243788704424131,
        "dpa":9932111872,
        "rawsize":3221225472
      }
    ]
  },
  {
    "dev":"nmem3",
    "index":[
      {
        "signature":"NAMESPACE_INDEX",
        "seq":2,
        "nslot":1016
      },
      {
        "signature":"NAMESPACE_INDEX",
        "seq":3,
        "nslot":1016
      }
    ],
    "label":[
      {
        "uuid":"359c68f7-efd9-410b-a727-1def27d574b5",
        "name":"number1",
        "slot":0,
        "position":3,
        "nlabel":4,
        "isetcookie":5125243788704424131,
        "dpa":268435456,
        "rawsize":3221225472
      },
      {
        "uuid":"c4047c15-7fa1-4f59-b60f-676f23326989",
        "name":"number2",
        "slot":1,
        "position":3,
        "nlabel":4,
        "isetcookie":5125243788704424131,
        "dpa":3489660928,
        "rawsize":3221225472
      },
      {
        "uuid":"56252c66-b1f1-435c-821a-67becef82f4c",
        "name":"number3",
        "slot":2,
        "position":3,
        "nlabel":4,
        "isetcookie":5125243788704424131,
        "dpa":6710886400,
        "rawsize":3221225472
      },
      {
        "uuid":"5b6e072c-5abb-43ff-ba8a-3bca6ee19068",
        "name":"number3",
        "slot":3,
        "position":3,
        "nlabel":4,
        "isetcookie":5125243788704424131,
        "dpa":9932111872,
        "rawsize":3221225472
      }
    ]
  },
  {
    "dev":"nmem0",
    "index":[
      {
        "signature":"NAMESPACE_INDEX",
        "seq":3,
        "nslot":1016
      },
      {
        "signature":"NAMESPACE_INDEX",
        "seq":1,
        "nslot":1016
      }
    ],
    "label":[
      {
        "uuid":"359c68f7-efd9-410b-a727-1def27d574b5",
        "name":"number1",
        "slot":0,
        "position":0,
        "nlabel":4,
        "isetcookie":5125243788704424131,
        "dpa":268435456,
        "rawsize":3221225472
      },
      {
        "uuid":"c4047c15-7fa1-4f59-b60f-676f23326989",
        "name":"number2",
        "slot":1,
        "position":0,
        "nlabel":4,
        "isetcookie":5125243788704424131,
        "dpa":3489660928,
        "rawsize":3221225472
      },
      {
        "uuid":"56252c66-b1f1-435c-821a-67becef82f4c",
        "name":"number3",
        "slot":2,
        "position":0,
        "nlabel":4,
        "isetcookie":5125243788704424131,
        "dpa":6710886400,
        "rawsize":3221225472
      },
      {
        "uuid":"5b6e072c-5abb-43ff-ba8a-3bca6ee19068",
        "name":"number3",
        "slot":3,
        "position":0,
        "nlabel":4,
        "isetcookie":5125243788704424131,
        "dpa":9932111872,
        "rawsize":3221225472
      },
      {
        "uuid":"07a28334-2937-4c07-8c84-1a4df9958fb5",
        "name":"number3",
        "slot":4,
        "position":0,
        "nlabel":4,
        "isetcookie":5125243788704424131,
        "dpa":9932111872,
        "rawsize":3221225472
      },
      {
        "uuid":"769236aa-0438-49c1-8769-67fcbf088469",
        "name":"number3",
        "slot":5,
        "position":0,
        "nlabel":4,
        "isetcookie":5125243788704424131,
        "dpa":9932111872,
        "rawsize":3221225472
      },
      {
        "uuid":"17b47468-9a92-418c-af07-05e5a7627de9",
        "name":"number3",
        "slot":6,
        "position":0,
        "nlabel":4,
        "isetcookie":5125243788704424131,
        "dpa":9932111872,
        "rawsize":3221225472
      },
      {
        "uuid":"752cc95d-8fb9-4ea4-a43b-6ce9c81f11f2",
        "name":"number4",
        "slot":7,
        "position":0,
        "nlabel":4,
        "isetcookie":5125243788704424131,
        "dpa":9932111872,
        "rawsize":3221225472
      }
    ]
  },
  {
    "dev":"nmem2",
    "index":[
      {
        "signature":"NAMESPACE_INDEX",
        "seq":2,
        "nslot":1016
      },
      {
        "signature":"NAMESPACE_INDEX",
        "seq":3,
        "nslot":1016
      }
    ],
    "label":[
      {
        "uuid":"359c68f7-efd9-410b-a727-1def27d574b5",
        "name":"number1",
        "slot":0,
        "position":2,
        "nlabel":4,
        "isetcookie":5125243788704424131,
        "dpa":268435456,
        "rawsize":3221225472
      },
      {
        "uuid":"c4047c15-7fa1-4f59-b60f-676f23326989",
        "name":"number2",
        "slot":1,
        "position":2,
        "nlabel":4,
        "isetcookie":5125243788704424131,
        "dpa":3489660928,
        "rawsize":3221225472
      },
      {
        "uuid":"56252c66-b1f1-435c-821a-67becef82f4c",
        "name":"number3",
        "slot":2,
        "position":2,
        "nlabel":4,
        "isetcookie":5125243788704424131,
        "dpa":6710886400,
        "rawsize":3221225472
      },
      {
        "uuid":"5b6e072c-5abb-43ff-ba8a-3bca6ee19068",
        "name":"number3",
        "slot":3,
        "position":2,
        "nlabel":4,
        "isetcookie":5125243788704424131,
        "dpa":9932111872,
        "rawsize":3221225472
      }
    ]
  }
]
read 4 nmems