1NVME-DISCOVER(1)                  NVMe Manual                 NVME-DISCOVER(1)
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NAME

6       nvme-discover - Send Get Log Page request to Discovery Controller.
7

SYNOPSIS

9       nvme discover
10                       [--transport=<trtype>     | -t <trtype>]
11                       [--traddr=<traddr>        | -a <traddr>]
12                       [--trsvcid=<trsvcid>      | -s <trsvcid>]
13                       [--host-traddr=<traddr>   | -w <traddr>]
14                       [--hostnqn=<hostnqn>      | -q <hostnqn>]
15                       [--raw=<filename>         | -r <filename>]
16

DESCRIPTION

18       Send one or more Get Log Page requests to a NVMe-over-Fabrics Discovery
19       Controller.
20
21       If no parameters are given, then nvme discover will attempt to find a
22       /etc/nvme/discovery.conf file to use to supply a list of Discovery
23       commands to run. If no /etc/nvme/discovery.conf file exists, the
24       command will quit with an error.
25
26       Otherwise, a specific Discovery Controller should be specified using
27       the --transport, --traddr, and if necessary the --trsvcid flags. A
28       Diѕcovery request will then be sent to the specified Discovery
29       Controller.
30

BACKGROUND

32       The NVMe-over-Fabrics specification defines the concept of a Discovery
33       Controller that an NVMe Host can query on a fabric network to discover
34       NVMe subsystems contained in NVMe Targets which it can connect to on
35       the network. The Discovery Controller will return Discovery Log Pages
36       that provide the NVMe Host with specific information (such as network
37       address and unique subsystem NQN) the NVMe Host can use to issue an
38       NVMe connect command to connect itself to a storage resource contained
39       in that NVMe subsystem on the NVMe Target.
40
41       Note that the base NVMe specfication defines the NQN (NVMe Qualified
42       Name) format which an NVMe endpoint (device, subsystem, etc) must
43       follow to guarantee a unique name under the NVMe standard. In
44       particular, the Host NQN uniquely identifies the NVMe Host, and may be
45       used by the the Discovery Controller to control what NVMe Target
46       resources are allocated to the NVMe Host for a connection.
47
48       A Discovery Controller has it’s own NQN defined in the
49       NVMe-over-Fabrics specification, nqn.2014-08.org.nvmexpress.discovery.
50       All Discovery Controllers must use this NQN name. This NQN is used by
51       default by nvme-cli for the discover command.
52

OPTIONS

54       -t <trtype>, --transport=<trtype>
55           This field specifies the network fabric being used for a
56           NVMe-over-Fabrics network. Current string values include:
57
58           ┌──────┬────────────────────────────┐
59           │Value │ Definition                 │
60           ├──────┼────────────────────────────┤
61           │rdma  │ The network fabric is an   │
62           │      │ rdma network (RoCE, iWARP, │
63           │      │ Infiniband, basic rdma,    │
64           │      │ etc)                       │
65           ├──────┼────────────────────────────┤
66           │fc    │ WIP The network fabric is  │
67           │      │ a Fibre Channel network.   │
68           ├──────┼────────────────────────────┤
69           │loop  │ Connect to a NVMe over     │
70           │      │ Fabrics target on the      │
71           │      │ local host                 │
72           └──────┴────────────────────────────┘
73
74       -a <traddr>, --traddr=<traddr>
75           This field specifies the network address of the Discovery
76           Controller. For transports using IP addressing (e.g. rdma) this
77           should be an IP-based (ex. IPv4) address.
78
79       -s <trsvcid>, --trsvcid=<trsvcid>
80           This field specifies the transport service id. For transports using
81           IP addressing (e.g. rdma) this field is the port number. By
82           default, the IP port number for the RDMA transport is 4420.
83
84       -q <hostnqn>, --hostnqn=<hostnqn>
85           Overrides the default host NQN that identifies the NVMe Host. If
86           this option is not specified, the default is read from
87           /etc/nvme/hostnqn first. If that does not exist, the autogenerated
88           NQN value from the NVMe Host kernel module is used next.
89
90       -w <traddr>, --host-traddr=<traddr>
91           This field specifies the network address used on the host to
92           connect to the Discovery Controller.
93
94       -r <filename>, --raw=<filename>
95           This field will take the output of the nvme discover command and
96           dump it to a raw binary file. By default nvme discover will dump
97           the output to stdout.
98

EXAMPLES

100       ·   Query the Discover Controller with IP4 address 192.168.1.3 for all
101           resources allocated for NVMe Host name host1-rogue-nqn on the RDMA
102           network. Port 4420 is used by default:
103
104               # nvme discover --transport=rdma --traddr=192.168.1.3 \
105               --hostnqn=host1-rogue-nqn
106
107       ·   Issue a nvme discover command using a /etc/nvme/discovery.conf
108           file:
109
110           # Machine default 'nvme discover' commands.  Query the
111           # Discovery Controller's two ports (some resources may only
112           # be accessible on a single port).  Note an official
113           # nqn (Host) name defined in the NVMe specification is being used
114           # in this example.
115           -t rdma -a 192.168.69.33 -s 4420 -q nqn.2014-08.com.example:nvme:nvm-subsystem-sn-d78432
116           -t rdma -a 192.168.1.4   -s 4420 -q nqn.2014-08.com.example:nvme:nvm-subsystem-sn-d78432
117
118           At the prompt type "nvme discover".
119

SEE ALSO

121       nvme-connect(1) nvme-connect-all(1)
122

AUTHORS

124       This was written by Jay Freyensee[1] for Keith Busch[2].
125

NVME

127       Part of the nvme-user suite
128

NOTES

130        1. Jay Freyensee
131           mailto:james.p.freyensee@intel.com
132
133        2. Keith Busch
134           mailto:keith.busch@intel.com
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138NVMe                              06/05/2018                  NVME-DISCOVER(1)
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