NAME

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

SYNOPSIS

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

DESCRIPTION

       The namespace label area is a small persistent partition of capacity available on some
       NVDIMM devices. The label area is used to provision one, or more, namespaces from regions.
       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

       <memory device(s)>
           A nmemX device name, or a dimm id number. Restrict the operation to the specified
           dimm(s). The keyword all can be specified to indicate the lack of any restriction,
           however this is the same as not supplying a --dimm option at all.

       -s, --size=
           Limit the operation to the given number of bytes. A size of 0 indicates to operate
           over the entire label capacity.

       -O, --offset=
           Begin the operation at the given offset into the label area.

       -b, --bus=
           A bus id number, or a provider string (e.g. "ACPI.NFIT"). Restrict the operation to
           the specified bus(es). The keyword all can be specified to indicate the lack of any
           restriction, however this is the same as not supplying a --bus option at all.

       -v
           Turn on verbose debug messages in the library (if ndctl was built with logging and
           debug enabled).

       -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

COPYRIGHT

       Copyright © 2016 - 2022, Intel Corporation. License GPLv2: GNU GPL version 2
       http://gnu.org/licenses/gpl.html. This is free software: you are free to change and
       redistribute it. There is NO WARRANTY, to the extent permitted by law.

SEE ALSO

       ndctl-create-namespace(1), UEFI NVDIMM Label Protocol
       <http://www.uefi.org/sites/default/files/resources/UEFI_Spec_2_7.pdf>