1NVME-READ(1) NVMe Manual NVME-READ(1)
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6 nvme-read - Send an NVMe Read command, provide results
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9 nvme-read <device> [--start-block=<slba> | -s <slba>]
10 [--block-count=<nlb> | -c <nlb>]
11 [--data-size=<size> | -z <size>]
12 [--metadata-size=<size> | -y <size>]
13 [--ref-tag=<reftag> | -r <reftag>]
14 [--data=<data-file> | -d <data-file>]
15 [--metadata=<metadata-file> | -M <metadata-file>]
16 [--prinfo=<prinfo> | -p <prinfo>]
17 [--app-tag-mask=<appmask> | -m <appmask>]
18 [--app-tag=<apptag> | -a <apptag>]
19 [--limited-retry | -l]
20 [--force-unit-access | -f]
21 [--dir-type=<type> | -T <type>]
22 [--dir-spec=<spec> | -S <spec>]
23 [--dsm=<dsm> | -D <dsm>]
24 [--show-command | -v]
25 [--dry-run | -w]
26 [--latency | -t]
27 [--storage-tag<storage-tag> | -g <storage-tag>]
28 [--storage-tag-check | -C ]
29 [--force]
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32 The Read command reads the logical blocks specified by the command from
33 the medium and copies to the data data buffer provided. Will use stdout
34 by default if you don’t provide a file.
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37 --start-block=<slba>, -s <slba>
38 Start block.
39 --block-count, -c
41 The number of blocks to transfer. This is a zeroes based value to
42 align with the kernel’s use of this field. (ie. 0 means transfer 1
43 block).
44 --data-size=<size>, -z <size>
46 Size of data, in bytes.
47 --metadata-size=<size>, -y <size>
49 Size of metadata in bytes.
50 --data=<data-file>, -d <data-file>
52 Data file. If none provided, contents are sent to STDOUT.
53 --metadata=<metadata-file>, -M <metadata-file>
55 Metadata file, if necessary.
56 --prinfo=<prinfo>, -p <prinfo>
58 Protection Information field definition.
59 ┌────┬────────────────────────────┐
61 │Bit │ Description │
62 ├────┼────────────────────────────┤
63 │3 │ PRACT: Protection │
64 │ │ Information Action. When │
65 │ │ set to 1, PI is │
66 │ │ stripped/inserted on │
67 │ │ read/write when the block │
68 │ │ format’s metadata size is │
69 │ │ 8. When set to 0, metadata │
70 │ │ is passes. │
71 ├────┼────────────────────────────┤
72 │2:0 │ PRCHK: Protection │
73 │ │ Information Check: │
74 ├────┼────────────────────────────┤
75 │2 │ Set to 1 enables checking │
76 │ │ the guard tag │
77 ├────┼────────────────────────────┤
78 │1 │ Set to 1 enables checking │
79 │ │ the application tag │
80 ├────┼────────────────────────────┤
81 │0 │ Set to 1 enables checking │
82 │ │ the reference tag │
83 └────┴────────────────────────────┘
84 --ref-tag=<reftag>, -r <reftag>
86 Optional reftag when used with protection information.
87 --app-tag-mask=<appmask>, -m <appmask>
89 Optional application tag mask when used with protection
90 information.
91 --force-unit-access, -f
93 Set the force-unit access flag.
94 -T <type>, --dir-type=<type>
96 Optional directive type. The nvme-cli only enforces the value be in
97 the defined range for the directive type, though the NVMe
98 specification (1.3a) defines only one directive, 01h, for write
99 stream identifiers.
100 -S <spec>, --dir-spec=<spec>
102 Optional field for directive specifics. When used with write
103 streams, this value is defined to be the write stream identifier.
104 The nvme-cli will not validate the stream requested is within the
105 controller’s capabilities.
106 -D <dsm>, --dsm=<dsm>
108 The optional data set management attributes for this command. The
109 argument for this is the least significant 8 bits of the DSM field
110 in a write command; the most significant 16 bits of the field come
111 from the directive specific field, if used. This may be used to set
112 attributes for the LBAs being written, like access frequency, type,
113 latency, among other things, as well as yet to be defined types.
114 Please consult the NVMe specification for detailed breakdown of how
115 to use this field.
116 -v, --show-cmd
118 Print out the command to be sent.
119 -w, --dry-run
121 Do not actually send the command. If want to use --dry-run option,
122 --show-cmd option must be set. Otherwise --dry-run option will be
123 ignored.
124 -t, --latency
126 Print out the latency the IOCTL took (in us).
127 -g <storage-tag>, --storage-tag=<storage-tag>
129 Variable Sized Expected Logical Block Storage Tag(ELBST).
130 -C, --storage-tag-check
132 This flag enables Storage Tag field checking as part of end-to-end
133 data protection processing.
134 --force
136 Ignore namespace is currently busy and performed the operation even
137 though.
138
140 No examples yet.
141
143 Part of the nvme-user suite
144NVMe 09/29/2023 NVME-READ(1)