Comment 0 for bug 1811785

On ubuntu 18.04.1 :

1°) With 4.15.0-43 two default namespaces in raw mode are visible while there shouldn't be any but no settings change could be applied.

root@server:~# ndctl list -R
[
  {
    "dev":"region1",
    "size":103079215104,
    "available_size":0,
    "type":"pmem",
    "numa_node":1,
    "persistence_domain":"unknown"
  },
  {
    "dev":"region0",
    "size":103079215104,
    "available_size":0,
    "type":"pmem",
    "numa_node":0,
    "persistence_domain":"unknown"
  }
]

root@server:~# ndctl list
[
  {
    "dev":"namespace1.0",
    "mode":"raw",
    "size":103079215104,
    "sector_size":512,
    "blockdev":"pmem1",
    "numa_node":1
  },
  {
    "dev":"namespace0.0",
    "mode":"raw",
    "size":103079215104,
    "sector_size":512,
    "blockdev":"pmem0",
    "numa_node":0
  }
]

root@server:~# ndctl create-namespace --reconfig=namespace1.0 --type=pmem --mode=sector -f
libndctl: sizeof_namespace_index: nmem10: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem10: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem10: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem10: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem10: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem10: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem10: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem10: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem10: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem10: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem7: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem7: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem7: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem7: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem7: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem7: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem7: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem7: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem7: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem7: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem9: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem9: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem9: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem9: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem9: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem9: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem9: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem9: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem9: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem9: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem6: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem6: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem6: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem6: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem6: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem6: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem6: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem6: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem6: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem6: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem11: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem11: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem11: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem11: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem11: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem11: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem11: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem11: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem11: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem11: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem8: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem8: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem8: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem8: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem8: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem8: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem8: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem8: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem8: label area (1024) too small to host (256 byte) labels
libndctl: sizeof_namespace_index: nmem8: label area (1024) too small to host (256 byte) labels
failed to reconfigure namespace: No such device

2°) With 4.18.0-13 no active namespaces are seen which seems more coherent for non initialized NVDIMM-N with labels but no namespace can be created.

Both patches (kernel & ndctl) listed in the github issue below needs to be applied in order to get them working properly. Tested against the current hwe 4.18 kernel.

https://github.com/pmem/ndctl/issues/78