1NVME-DISCOVER(1) NVMe Manual NVME-DISCOVER(1)
2
6 nvme-discover - Send Get Log Page request to Discovery Controller.
7
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
18 Send one or more Get Log Page requests to a NVMe-over-Fabrics Discovery
19 Controller.
20 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 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
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 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 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
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 ┌──────┬────────────────────────────┐
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 -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 -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 -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 -w <traddr>, --host-traddr=<traddr>
91 This field specifies the network address used on the host to
92 connect to the Discovery Controller.
93 -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
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 # nvme discover --transport=rdma --traddr=192.168.1.3 \
105 --hostnqn=host1-rogue-nqn
106 · Issue a nvme discover command using a /etc/nvme/discovery.conf
108 file:
109 # 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 At the prompt type "nvme discover".
119
121 nvme-connect(1) nvme-connect-all(1)
122
124 This was written by Jay Freyensee[1] for Keith Busch[2].
125
127 Part of the nvme-user suite
128
130 1. Jay Freyensee
131 mailto:james.p.freyensee@intel.com
132 2. Keith Busch
134 mailto:keith.busch@intel.com
135NVMe 06/05/2018 NVME-DISCOVER(1)