NAME¶

nvme-discover - Send Get Log Page request to Discovery Controller.

SYNOPSIS¶

nvme discover


                [--transport=<trtype>     | -t <trtype>]


                [--traddr=<traddr>        | -a <traddr>]


                [--trsvcid=<trsvcid>      | -s <trsvcid>]


                [--host-traddr=<traddr>   | -w <traddr>]


                [--hostnqn=<hostnqn>      | -q <hostnqn>]


                [--hostid=<hostid>        | -I <hostid>]


                [--raw=<filename>         | -r <filename>]


                [--keep-alive-tmo=<sec>   | -k <sec>]


                [--reconnect-delay=<#>    | -c <#>]


                [--ctrl-loss-tmo=<#>      | -l <#>]


                [--hdr_digest             | -g]


                [--data_digest            | -G]


                [--nr-io-queues=<#>       | -i <#>]


                [--nr-write-queues=<#>    | -W <#>]


                [--nr-poll-queues=<#>     | -P <#>]


                [--queue-size=<#>         | -Q <#>]

DESCRIPTION¶

Send one or more Get Log Page requests to a NVMe-over-Fabrics Discovery Controller.

If no parameters are given, then nvme discover will attempt to find a /etc/nvme/discovery.conf file to use to supply a list of Discovery commands to run. If no /etc/nvme/discovery.conf file exists, the command will quit with an error.

Otherwise, a specific Discovery Controller should be specified using the --transport, --traddr, and if necessary the --trsvcid flags. A Diѕcovery request will then be sent to the specified Discovery Controller.

BACKGROUND¶

The NVMe-over-Fabrics specification defines the concept of a Discovery Controller that an NVMe Host can query on a fabric network to discover NVMe subsystems contained in NVMe Targets which it can connect to on the network. The Discovery Controller will return Discovery Log Pages that provide the NVMe Host with specific information (such as network address and unique subsystem NQN) the NVMe Host can use to issue an NVMe connect command to connect itself to a storage resource contained in that NVMe subsystem on the NVMe Target.

Note that the base NVMe specification defines the NQN (NVMe Qualified Name) format which an NVMe endpoint (device, subsystem, etc) must follow to guarantee a unique name under the NVMe standard. In particular, the Host NQN uniquely identifies the NVMe Host, and may be used by the the Discovery Controller to control what NVMe Target resources are allocated to the NVMe Host for a connection.

A Discovery Controller has it’s own NQN defined in the NVMe-over-Fabrics specification, nqn.2014-08.org.nvmexpress.discovery. All Discovery Controllers must use this NQN name. This NQN is used by default by nvme-cli for the discover command.

OPTIONS¶

-t <trtype>, --transport=<trtype>

-a <traddr>, --traddr=<traddr>

-s <trsvcid>, --trsvcid=<trsvcid>

-w <traddr>, --host-traddr=<traddr>

-q <hostnqn>, --hostnqn=<hostnqn>

-I <hostid>, --hostid=<hostid>

-r <filename>, --raw=<filename>

-k <#>, --keep-alive-tmo=<#>

-c <#>, --reconnect-delay=<#>

-l <#>, --ctrl-loss-tmo=<#>

-g, --hdr_digest

-G, --data_digest

-i <#>, --nr-io-queues=<#>

-W <#>, --nr-write-queues=<#>

-P <#>, --nr-poll-queues=<#>

-Q <#>, --queue-size=<#>

EXAMPLES¶

# nvme discover --transport=rdma --traddr=192.168.1.3 \
--hostnqn=host1-rogue-nqn

# Machine default 'nvme discover' commands.  Query the
# Discovery Controller's two ports (some resources may only
# be accessible on a single port).  Note an official
# nqn (Host) name defined in the NVMe specification is being used
# in this example.
-t rdma -a 192.168.69.33 -s 4420 -q nqn.2014-08.com.example:nvme:nvm-subsystem-sn-d78432
-t rdma -a 192.168.1.4   -s 4420 -q nqn.2014-08.com.example:nvme:nvm-subsystem-sn-d78432
At the prompt type "nvme discover".

SEE ALSO¶

nvme-connect(1) nvme-connect-all(1)

AUTHORS¶

This was written by Jay Freyensee[1] for Keith Busch[2].

NVME¶

Part of the nvme-user suite

NOTES¶

1.

Jay Freyensee

2.

Keith Busch