1NDCTL-READ-INFOBLO(1)                                    NDCTL-READ-INFOBLO(1)
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NAME

6       ndctl-read-infoblock - read and optionally parse the info-block a
7       namespace
8

SYNOPSIS

10       ndctl read-infoblock <namespace0.0> [<namespace1.0>..<namespaceN.Y>] [<options>]
11

DESCRIPTION

13       As described in the theory of operation section of
14       linkndctl:ndctl-create-namespace[1], the raw capacity of a namespace
15       may encapsulate a personality, or mode of operation. Specifically, the
16       mode may be set to one of "sector", "fsdax", and "devdax". Each of
17       those modes is defined by an info-block format that uniquely identifies
18       the mode of operation. The read-infoblock command knows the location
19       (relative to the start of the namespace) and field definition of those
20       data structures.
21
22       Note that unlike a partition table info-block is not exposed by
23       default, so the namespace needs to be disabled before the info-block
24       can be accessed.
25

EXAMPLE

27           ndctl disable-namespace namespace0.0
28           disabled 1 namespace
29           ndctl read-infoblock -j namespace0.0
30           [
31             {
32               "dev":"namespace0.0",
33               "signature":"NVDIMM_PFN_INFO",
34               "uuid":"56b11990-66b1-4d91-9cac-ca084c051259",
35               "parent_uuid":"00000000-0000-0000-0000-000000000000",
36               "flags":0,
37               "version":"1.3",
38               "dataoff":69206016,
39               "npfns":1031680,
40               "mode":2,
41               "start_pad":0,
42               "end_trunc":0,
43               "align":2097152
44             }
45           ]
46

OPTIONS

48       <namespace(s)>
49           One or more namespaceX.Y device names. The keyword all can be
50           specified to operate on every namespace in the system, optionally
51           filtered by bus id (see --bus= option), or region id (see --region=
52           option).
53
54       -V, --verify
55           Attempt to validate that the info-block is self consistent by
56           validating the embedded checksum, and that info-block formats that
57           contain a parent-uuid attribute also match the base-uuid of the
58           namespace.
59
60       -o, --output
61           Output file
62
63       -j, --json
64           Parse the info-block data into json.
65
66       -u, --human
67           Enable json output and convert number formats to human readable
68           strings, for example show the size in terms of "KB", "MB", "GB",
69           etc instead of a signed 64-bit numbers per the JSON interchange
70           format (implies --json).
71
72       -r, --region=
73           A regionX device name, or a region id number. Restrict the
74           operation to the specified region(s). The keyword all can be
75           specified to indicate the lack of any restriction, however this is
76           the same as not supplying a --region option at all.
77

79       Copyright © 2016 - 2022, Intel Corporation. License GPLv2: GNU GPL
80       version 2 http://gnu.org/licenses/gpl.html. This is free software: you
81       are free to change and redistribute it. There is NO WARRANTY, to the
82       extent permitted by law.
83

SEE ALSO

85       linkndctl:ndctl-create-namespace[1], UEFI NVDIMM Label Protocol[1]
86

NOTES

88        1. UEFI NVDIMM Label Protocol
89           http://www.uefi.org/sites/default/files/resources/UEFI_Spec_2_7.pdf
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93                                  03/08/2022             NDCTL-READ-INFOBLO(1)
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