// SPDX-License-Identifier: GPL-2.0

ndctl-init-labels(1)
====================

NAME
----
ndctl-init-labels - initialize the label data area on a dimm or set of dimms

SYNOPSIS
--------
[verse]
'ndctl init-labels' <nmem0> [<nmem1>..<nmemN>] [<options>]

include::labels-description.txt[]
By default, and in kernels prior to v4.10, the kernel only honors labels
when a DIMM aliases PMEM and BLK capacity. Starting with v4.10 the
kernel will honor labels for sub-dividing PMEM if all the DIMMs in an
interleave set / region have a valid namespace index block.

This command can be used to initialize the namespace index block if it
is missing or reinitialize it if it is damaged.  Note that
reinitialization effectively destroys all existing namespace labels on
the DIMM.

EXAMPLE
-------
Find the DIMMs that comprise a given region:
----
# ndctl list -RD --region=region1
{
  "dimms":[
    {
      "dev":"nmem0",
      "id":"8680-56341200"
    }
  ],
  "regions":[
    {
      "dev":"region1",
      "size":268435456,
      "available_size":0,
      "type":"pmem",
      "mappings":[
        {
          "dimm":"nmem0",
          "offset":13958643712,
          "length":268435456
        }
      ]
    }
  ]
}
----

Disable that region so the DIMM label area can be written from
userspace:
----
# ndctl disable-region region1
----

Initialize labels:
----
# ndctl init-labels nmem0
----

Re-enable the region:
----
# ndctl enable-region region1
----

Create a namespace in that region:
----
# ndctl create-namespace --region=region1
----

OPTIONS
-------
include::labels-options.txt[]
-f::
--force::
	Force initialization of the label space even if there appears to
	be an existing / valid namespace index.  Warning, this will
	destroy all defined namespaces on the dimm.

-V::
--label-version::
	Initialize with a specific version of labels from the namespace
	label specification. Defaults to 1.1

include::../copyright.txt[]

SEE ALSO
--------
linkndctl:ndctl-create-namespace[1],
http://www.uefi.org/sites/default/files/resources/UEFI_Spec_2_7.pdf[UEFI NVDIMM Label Protocol]
