1NDCTL-INIT-LABELS(1)             ndctl Manual             NDCTL-INIT-LABELS(1)
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NAME

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

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

13       The namespace label area is a small persistent partition of capacity
14       available on some NVDIMM devices. The label area is used to resolve
15       aliasing between pmem and blk capacity by delineating namespace
16       boundaries. By default, and in kernels prior to v4.10, the kernel only
17       honors labels when a DIMM aliases PMEM and BLK capacity. Starting with
18       v4.10 the kernel will honor labels for sub-dividing PMEM if all the
19       DIMMs in an interleave set / region have a valid namespace index block.
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21       This command can be used to initialize the namespace index block if it
22       is missing or reinitialize it if it is damaged. Note that
23       reinitialization effectively destroys all existing namespace labels on
24       the DIMM.
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EXAMPLE

27       Find the DIMMs that comprise a given region:
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29
30           .ft C
31           # ndctl list -RD --region=region1
32           {
33             "dimms":[
34               {
35                 "dev":"nmem0",
36                 "id":"8680-56341200"
37               }
38             ],
39             "regions":[
40               {
41                 "dev":"region1",
42                 "size":268435456,
43                 "available_size":0,
44                 "type":"pmem",
45                 "mappings":[
46                   {
47                     "dimm":"nmem0",
48                     "offset":13958643712,
49                     "length":268435456
50                   }
51                 ]
52               }
53             ]
54           }
55           .ft
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57
58       Disable that region so the DIMM label area can be written from
59       userspace:
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62           .ft C
63           # ndctl disable-region region1
64           .ft
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66
67       Initialize labels:
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70           .ft C
71           # ndctl init-labels nmem0
72           .ft
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75       Re-enable the region:
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78           .ft C
79           # ndctl enable-region region1
80           .ft
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82
83       Create a namespace in that region:
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86           .ft C
87           # ndctl create-namespace --region=region1
88           .ft
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OPTIONS

92       <memory device(s)>
93           A nmemX device name, or a dimm id number. Restrict the operation to
94           the specified dimm(s). The keyword all can be specified to indicate
95           the lack of any restriction, however this is the same as not
96           supplying a --dimm option at all.
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98       -s, --size=
99           Limit the operation to the given number of bytes. A size of 0
100           indicates to operate over the entire label capacity.
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102       -O, --offset=
103           Begin the operation at the given offset into the label area.
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105       -b, --bus=
106           A bus id number, or a provider string (e.g. "ACPI.NFIT"). Restrict
107           the operation to the specified bus(es). The keyword all can be
108           specified to indicate the lack of any restriction, however this is
109           the same as not supplying a --bus option at all.
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111       -v
112           Turn on verbose debug messages in the library (if ndctl was built
113           with logging and debug enabled).
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115       -f, --force
116           Force initialization of the label space even if there appears to be
117           an existing / valid namespace index. Warning, this will destroy all
118           defined namespaces on the dimm.
119
120       -V, --label-version
121           Initialize with a specific version of labels from the namespace
122           label specification. Defaults to 1.1
123

125       Copyright © 2016 - 2020, Intel Corporation. License GPLv2: GNU GPL
126       version 2 http://gnu.org/licenses/gpl.html. This is free software: you
127       are free to change and redistribute it. There is NO WARRANTY, to the
128       extent permitted by law.
129

SEE ALSO

131       ndctl-create-namespace(1), UEFI NVDIMM Label Protocol[1]
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NOTES

134        1. UEFI NVDIMM Label Protocol
135           http://www.uefi.org/sites/default/files/resources/UEFI_Spec_2_7.pdf
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139ndctl 71.1                        07/22/2021              NDCTL-INIT-LABELS(1)
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