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NVME-READ(1)			   NVMe Manual			    NVME-READ(1)

NAME
     nvme-read - Send an NVMe Read command, provide results

SYNOPSIS
     nvme-read <device> [--start-block=<slba> | -s <slba>]
			     [--block-count=<nlb> | -c <nlb>]
			     [--data-size=<size> | -z <size>]
			     [--metadata-size=<size> | -y <size>]
			     [--ref-tag=<reftag> | -r <reftag>]
			     [--data=<data-file> | -d <data-file>]
			     [--metadata=<metadata-file> | -M <metadata-file>]
			     [--prinfo=<prinfo> | -p <prinfo>]
			     [--app-tag-mask=<appmask> | -m <appmask>]
			     [--app-tag=<apptag> | -a <apptag>]
			     [--limited-retry | -l] [--force-unit-access | -f]
			     [--dir-type=<type> | -T <type>]
			     [--dir-spec=<spec> | -S <spec>] [--dsm=<dsm> | -D <dsm>]
			     [--show-command | -V] [--dry-run | -w] [--latency | -t]
			     [--storage-tag<storage-tag> | -g <storage-tag>]
			     [--storage-tag-check | -C] [--force]
			     [--output-format=<fmt> | -o <fmt>] [--verbose | -v]
			     [--timeout=<timeout>]

DESCRIPTION
     The Read command reads the logical blocks specified by the command from the
     medium  and copies to the data data buffer provided. Will use stdout by de-
     fault if you don't provide a file.

OPTIONS
     -s <slba>, --start-block=<slba>
	 Start block.

     -c, --block-count
	 The number of blocks to transfer. This is a zeroes based value to align
	 with the kernel's use of this field. (ie. 0 means transfer 1 block).

     -z <size>, --data-size=<size>
	 Size of data, in bytes.

     -y <size>, --metadata-size=<size>
	 Size of metadata in bytes.

     -d <data-file>, --data=<data-file>
	 Data file. If none provided, contents are sent to STDOUT.

     -M <metadata-file>, --metadata=<metadata-file>
	 Metadata file, if necessary.

     -p <prinfo>, --prinfo=<prinfo>
	 Protection Information field definition.
	 +-----+-----------------------------+
	 | Bit | Description		     |
	 +-----+-----------------------------+
	 | 3   | PRACT: Protection  Informa- |
	 |     | tion Action. When set to 1, |
	 |     | PI  is stripped/inserted on |
	 |     | read/write when  the  block |
	 |     | format's  metadata  size is |
	 |     | 8. When set to 0,  metadata |
	 |     | is passes.		     |
	 +-----+-----------------------------+
	 | 2:0 | PRCHK:  Protection Informa- |
	 |     | tion Check:		     |
	 +-----+-----------------------------+
	 | 2   | Set to 1  enables  checking |
	 |     | the guard tag		     |
	 +-----+-----------------------------+
	 | 1   | Set  to  1 enables checking |
	 |     | the application tag	     |
	 +-----+-----------------------------+
	 | 0   | Set to 1  enables  checking |
	 |     | the reference tag	     |
	 +-----+-----------------------------+

     -r <reftag>, --ref-tag=<reftag>
	 Optional reftag when used with protection information.

     -m <appmask>, --app-tag-mask=<appmask>
	 Optional application tag mask when used with protection information.

     -f, --force-unit-access
	 Set the force-unit access flag.

     -T <type>, --dir-type=<type>
	 Optional directive type. The nvme-cli only enforces the value be in the
	 defined  range  for  the  directive type, though the NVMe specification
	 (1.3a) defines only one directive, 01h, for write stream identifiers.

     -S <spec>, --dir-spec=<spec>
	 Optional field for directive specifics. When used with  write	streams,
	 this  value  is defined to be the write stream identifier. The nvme-cli
	 will not validate the stream requested is within the controller's capa-
	 bilities.

     -D <dsm>, --dsm=<dsm>
	 The optional data set management attributes for this command. The argu-
	 ment for this is the least significant 8 bits of the  DSM  field  in  a
	 write	command; the most significant 16 bits of the field come from the
	 directive specific field, if used. This may be used to  set  attributes
	 for the LBAs being written, like access frequency, type, latency, among
	 other	things,  as  well as yet to be defined types. Please consult the
	 NVMe specification for detailed breakdown of how to use this field.

     -V, --show-cmd
	 Print out the command to be sent.

     -w, --dry-run
	 Do not actually send the command. If  want  to  use  --dry-run  option,
	 --show-cmd  option  must be set. Otherwise --dry-run option will be ig-
	 nored.

     -t, --latency
	 Print out the latency the IOCTL took (in us).

     -g <storage-tag>, --storage-tag=<storage-tag>
	 Variable Sized Expected Logical Block Storage Tag(ELBST).

     -C, --storage-tag-check
	 This flag enables Storage Tag field checking as part of end-to-end data
	 protection processing.

     --force
	 Ignore namespace is currently busy and  performed  the  operation  even
	 though.

     -o <fmt>, --output-format=<fmt>
	 Set  the  reporting  format  to normal, json or binary. Only one output
	 format can be used at a time.

     -v, --verbose
	 Increase the information detail in the output.

     --timeout=<timeout>
	 Override default timeout value. In milliseconds.

EXAMPLES
     No examples yet.

NVME
     Part of the nvme-user suite

NVMe				   10/31/2024			    NVME-READ(1)

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