1NVMETCLI(8)                                                        NVMETCLI(8)
2
3
4

NAME

6       nvmetcli - Configure NVMe-over-Fabrics Target.
7

USAGE

9           nvmetcli
10           nvmetcli clear
11           nvmetcli restore [filename.json]
12

DESCRIPTION

14       nvmetcli is a program used for viewing, editing, saving, and starting a
15       Linux kernel NVMe Target, used for an NVMe-over-Fabrics network
16       configuration. It allows an administrator to export a storage resource
17       (such as NVMe devices, files, and volumes) to a local block device and
18       expose them to remote systems based on the NVMe-over-Fabrics
19       specification from http://www.nvmexpress.org.
20
21       nvmetcli is run as root and has two modes:
22
23        1. An interactive configuration shell
24
25        2. Command-line mode which uses an argument
26

BACKGROUND

28       The term NQN used throughout this man page is the NVMe Qualified Name
29       format which an NVMe endpoint (device, subsystem, etc) must follow to
30       guarantee a unique name under the NVMe standard. Any name in a network
31       system setup can be used, but if it does not follow the NQN format, it
32       may not be unique on an NVMe-over-Fabrics network.
33
34       Note that some of the fields set for an NVMe Target port under
35       interactive mode are defined in the "Discovery Log Page" section of
36       NVMe-over-Fabrics specification. Each NVMe Target has a discovery
37       controller mechanism that an NVMe Host can use to determine the NVM
38       subsystems it can access. nvmetcli can be used to add a new record to
39       the discovery controller upon each new subsystem entry and port entry
40       that the newly created subsystem entry binds to (see OPTIONS and
41       EXAMPLES sections). Each NVMe Host only gets to see the discovery
42       entries defined in /subsystems/[NQN NAME]/allowed_hosts and the IP port
43       it is connected to the NVMe Target. An NVMe Host can retrieve these
44       discovery logs via the nvme-cli tool
45       (https://github.com/linux-nvme/nvme-cli).
46

OPTIONS

48       Interactive Configuration Shell
49
50       To start the interactive configuration shell, type nvmetcli on the
51       command-line. nvmetcli interacts with the Linux kernel NVMe Target
52       configfs subsystem starting at base nvmetcli directories /port,
53       /subsystem, and /host. Configuration changes entered by the
54       administrator are made immediately to the kernel target configuration.
55       The following commands can be used while in the interactive
56       configuration shell mode:
57
58       ┌───────────────────────────┬────────────────────────────┐
59       │                           │                            │
60       │cd                         │ Allows to move around the  │
61       │                           │ tree.                      │
62       ├───────────────────────────┼────────────────────────────┤
63       │                           │                            │
64       │ls                         │ Lists contents of current  │
65       │                           │ tree node.                 │
66       ├───────────────────────────┼────────────────────────────┤
67       │                           │                            │
68       │create [NQN name]/[#]      │ Create a new object using  │
69       │                           │ the specified name or      │
70       │                           │ number. If a [NQN          │
71       │                           │ name]/[#] is not           │
72       │                           │ specified, a random entry  │
73       │                           │ will be used.              │
74       ├───────────────────────────┼────────────────────────────┤
75       │                           │                            │
76       │delete [NQN name]/[#]      │ Delete an object with the  │
77       │                           │ specified name or number.  │
78       ├───────────────────────────┼────────────────────────────┤
79       │                           │                            │
80       │set attr                   │ Used under                 │
81       │allow_any_host=[0/1]       │ /subsystems/[NQN name] to  │
82       │                           │ specify if any NVMe Host   │
83       │                           │ can connect to the         │
84       │                           │ subsystem.                 │
85       ├───────────────────────────┼────────────────────────────┤
86       │                           │                            │
87       │set device path=[device    │ Used under                 │
88       │path]                      │ /subsystems/[NQN           
89       │                           │ name]/namespaces to set    │
90       │                           │ the (storage) device to be │
91       │                           │ used.                      │
92       ├───────────────────────────┼────────────────────────────┤
93       │                           │                            │
94       │set device nguid=[string]  │ Used under                 │
95       │                           │ /subsystems/[NQN           
96       │                           │ name]/namespaces to set    │
97       │                           │ the unique id of the       │
98       │                           │ device to the defined      │
99       │                           │ namespace.                 │
100       ├───────────────────────────┼────────────────────────────┤
101       │                           │                            │
102       │enable/disable             │ Used under                 │
103       │                           │ /subsystems/[NQN           
104       │                           │ name]/namespaces to enable │
105       │                           │ and disable the namespace. │
106       ├───────────────────────────┼────────────────────────────┤
107       │                           │                            │
108       │set addr [discovery log    │ Used under /ports/[#] to   │
109       │page field]=[string]       │ create a port which access │
110       │                           │ is allowed. See EXAMPLES   
111       │                           │ for more information.      │
112       ├───────────────────────────┼────────────────────────────┤
113       │                           │                            │
114       │saveconfig [filename.json] │ Save the NVMe Target       │
115       │                           │ configuration in .json     │
116       │                           │ format. Without specifying │
117       │                           │ the filename this will     │
118       │                           │ save as                    │
119       │                           │ /etc/nvmet/config.json.    │
120       │                           │ This file is in JSON       │
121       │                           │ format and can be edited   │
122       │                           │ directly using a prefered  │
123       │                           │ file editor.               │
124       ├───────────────────────────┼────────────────────────────┤
125       │                           │                            │
126       │exit                       │ Quits interactive          │
127       │                           │ configuration shell mode.  │
128       └───────────────────────────┴────────────────────────────┘
129
130       Command Line Mode
131
132       Typing nvmetcli [cmd] on the command-line will execute a command and
133       not enter the interactive configuration shell.
134
135       ┌────────────────────────┬───────────────────────────┐
136       │                        │                           │
137       │restore [filename.json] │ Loads a saved NVMe Target │
138       │                        │ configuration. Without    │
139       │                        │ specifying the filename   │
140       │                        │ this will use             │
141       │                        │ /etc/nvmet/config.json.   │
142       ├────────────────────────┼───────────────────────────┤
143       │                        │                           │
144       │clear                   │ Clears a current NVMe     │
145       │                        │ Target configuration.     │
146       └────────────────────────┴───────────────────────────┘
147

EXAMPLES

149       Make sure to run nvmetcli as root, the nvmet module is loaded, your
150       devices and all dependent modules are loaded, and configfs is mounted
151       on /sys/kernel/config using:
152
153           mount -t configs none /sys/kernel/config
154
155       The following section walks through a configuration example.
156
157       ·   To get started with the interactive mode and the nvmetcli command
158           prompt, type (in root):
159
160           # ./nvmetcli
161           ...>
162
163       ·   Create a subsystem. If you do not specify a name a NQN will be
164           generated, which is probably the best choice. We don’t do it here
165           as the name would be random:
166
167           > cd /subsystems
168           ...> create testnqn
169
170       ·   Add access for a specific NVMe Host by it’s NQN:
171
172           ...> cd /hosts
173           ...> create hostnqn
174           ...> cd /subsystems/testnqn
175           ...> set attr allow_any_host=0
176           ...> cd /subsystems/testnqn/allowed_hosts/
177           ...> create hostnqn
178
179       ·   Remove access of a subsystem by deleting the Host NQN:
180
181           ...> cd /subsystems/testnqn/allowed_hosts/
182           ...> delete hostnqn
183
184       ·   Alternatively this allows any Host to connect to the subsystsem.
185           Only use this in tightly controlled environments:
186
187           ...> cd /subsystems/testnqn/
188           ...> set attr allow_any_host=1
189
190       ·   Create a new namespace. If you do not specify a namespace ID the
191           fist unused one will be used:
192
193           ...> cd /subsystems/testnqn/namespaces
194           ...> create 1
195           ...> cd 1
196           ...> set device path=/dev/nvme0n1
197           ...> enable
198
199       Note that in the above setup the device_nguid attribute does not have
200       to be set for correct NVMe Target functionality (but to correctly match
201       a namespace to the exact device upon clear and restore operations, it
202       is advised to set the device_nguid parameter).
203
204       ·   Create a loopback port that can be used with nvme-loop module on
205           the same physical machine...
206
207           ...> cd /ports/
208           ...> create 1
209           ...> cd 1/
210           ...> set addr trtype=loop
211           ...> cd subsystems/
212           ...> create testnqn
213
214       ·   or create an RDMA (IB, RoCE, iWarp) port using IPv4 addressing.
215           4420 is the IANA assigned default port for NVMe over Fabrics using
216           RDMA:
217
218           ...> cd /ports/
219           ...> create 2
220           ...> cd 2/
221           ...> set addr trtype=rdma
222           ...> set addr adrfam=ipv4
223           ...> set addr traddr=192.168.6.68
224           ...> set addr trsvcid=4420
225           ...> cd subsystems/
226           ...> create testnqn
227
228       ·   or create an FC port. traddr is the WWNN/WWPN of the FC port.
229
230           ...> cd /ports/
231           ...> create 3
232           ...> cd 3/
233           ...> set addr trtype=fc
234           ...> set addr adrfam=fc
235           ...> set addr traddr=nn-0x1000000044001123:pn-0x2000000055001123
236           ...> set addr trsvcid=none
237           ...> cd subsystems/
238           ...> create testnqn
239
240       ·   Saving the NVMe Target configuration:
241
242           ./nvmetcli
243           ...> saveconfig test.json
244
245       ·   Loading an NVMe Target configuration:
246
247             ./nvmetcli restore test.json
248
249       ·   Clearing a current NVMe Target configuration:
250
251             ./nvmetcli clear
252

ADDITIONAL INFORMATION

254       nvmetcli has the ability to start and stop the NVMe Target
255       configuration on boot and shutdown through the systemctl Linux utility
256       via a .service file. nvmetcli package comes with nvmet.service which
257       when installed, it can automatically restore the default, saved NVMe
258       Target configuration from /etc/nvmet/config.json. nvmet.service can be
259       installed in directories such as /lib/systemd/system.
260
261       To explicitly enable the service, type:
262
263             systemctl enable nvmet
264
265       To explicitly disable the service, type:
266
267             systemctl disable nvmet
268
269       See also systemctl(1).
270

AUTHORS

272       This man page was written by Jay Freyensee[1]. nvmetcli was originally
273       written by Christoph Hellwig[2].
274

REPORTING BUGS & DEVELOPMENT

276       Please send patches and bug reports to
277       linux-nvme@lists.infradead.org[3] for review and acceptance.
278

LICENSE

280       nvmetcli is licensed under the Apache License, Version 2.0. Software
281       distributed under this license is distributed on an "AS IS" BASIS,
282       WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either expressed or
283       implied.
284

NOTES

286        1. Jay Freyensee
287           mailto:james.p.freyensee@intel.com
288
289        2. Christoph Hellwig
290           mailto:hch@infradead.org
291
292        3. linux-nvme@lists.infradead.org
293           mailto:linux-nvme@lists.infradead.org
294
295
296
297                                  01/29/2020                       NVMETCLI(8)
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