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-check<storage-tag-check> | -C <storage-tag-check>]

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 default if you don’t provide a
       file.

OPTIONS

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

       --block-count, -c
           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).

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

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

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

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

       --prinfo=<prinfo>, -p <prinfo>
           Protection Information field definition.

           ┌────┬──────────────────────────────────┐
           │Bit │ Description                      │
           ├────┼──────────────────────────────────┤
           │3   │ PRACT: Protection Information    │
           │    │ 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 Information    │
           │    │ 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                    │
           └────┴──────────────────────────────────┘

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

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

       --force-unit-access, -f
           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 specifcation (1.3a) defines only one
           directive, 01h, for write stream idenfiers.

       -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 capabilities.

       -D <dsm>, --dsm=<dsm>
           The optional data set management attributes for this command. The argument for this is
           the lower 16 bits of the DSM field in a write command; the upper 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 ignored.

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

       --storage-tag-check=<storage-tag-check>, -C <storage-tag-check>
           This bit specifies the Storage Tag field shall be checked as part of end-to-end data
           protection processing.

EXAMPLES

       No examples yet.

NVME

       Part of the nvme-user suite