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diff --git a/Documentation/nvmetcli.txt b/Documentation/nvmetcli.txt new file mode 100644 index 0000000..43e9f97 --- /dev/null +++ b/Documentation/nvmetcli.txt @@ -0,0 +1,267 @@ +nvmetcli(8) +=========== + +NAME +---- +nvmetcli - Configure NVMe-over-Fabrics Target. + +USAGE +------ +[verse] +nvmetcli +nvmetcli clear +nvmetcli restore [filename.json] + +DESCRIPTION +----------- +*nvmetcli* is a program used for viewing, editing, saving, +and starting a Linux kernel NVMe Target, used for an NVMe-over-Fabrics +network configuration. It allows an administrator to export +a storage resource (such as NVMe devices, files, and volumes) +to a local block device and expose them to remote systems +based on the NVMe-over-Fabrics specification from http://www.nvmexpress.org. + +*nvmetcli* is run as root and has two modes: + +1. An interactive configuration shell +2. Command-line mode which uses an argument + +BACKGROUND +---------- +The term *NQN* used throughout this man page is the *NVMe Qualified +Name* format which an NVMe endpoint (device, subsystem, etc) must +follow to guarantee a unique name under the NVMe standard. Any +name in a network system setup can be used, but if it does not +follow the NQN format, it may not be unique on an NVMe-over-Fabrics network. + +Note that some of the fields set for an NVMe Target port under +interactive mode are defined in the "Discovery Log Page" section of +NVMe-over-Fabrics specification. Each NVMe Target has a +discovery controller mechanism that an NVMe Host can use to determine +the NVM subsystems it can access. *nvmetcli* can be used to add +a new record to the discovery controller upon each new subsystem +entry and port entry that the newly created subsystem entry binds +to (see *OPTIONS* and *EXAMPLES* sections). Each NVMe +Host only gets to see the discovery entries defined in +*/subsystems/[NQN NAME]/allowed_hosts* and the IP port it is connected +to the NVMe Target. An NVMe Host can retrieve these discovery logs via +the nvme-cli tool (https://github.com/linux-nvme/nvme-cli). + +OPTIONS +------- +*Interactive Configuration Shell* + +To start the interactive configuration shell, type *nvmetcli* on +the command-line. nvmetcli interacts with the Linux kernel +NVMe Target configfs subsystem starting at base +nvmetcli directories **/port**, **/subsystem**, and **/host**. +Configuration changes entered by the administrator are made +immediately to the kernel target configuration. The +following commands can be used while in the interactive configuration +shell mode: +[] +|================== +| cd | Allows to move around the tree. +| ls | Lists contents of current tree node. +| create [NQN name]/[#] | Create a new object using the specified name + or number. If a [NQN name]/[#] is not specified, + a random entry will be used. +| delete [NQN name]/[#] | Delete an object with the specified name or number. +| set attr allow_any_host=[0/1] | Used under */subsystems/[NQN name]* to + specify if any NVMe Host can connect to + the subsystem. +| set device path=[device path] | Used under + */subsystems/[NQN name]/namespaces* + to set the (storage) device to be used. +| set device nguid=[string] | Used under + */subsystems/[NQN name]/namespaces* + to set the unique id of the device to + the defined namespace. +| enable/disable | Used under + */subsystems/[NQN name]/namespaces* + to enable and disable the namespace. +| set addr [discovery log page field]=[string] | Used under */ports/[#]* + to create a port which + access is allowed. See + *EXAMPLES* for more + information. +| saveconfig [filename.json] | Save the NVMe Target configuration in .json + format. Without specifying the + filename this will save as + */etc/nvmet/config.json*. This file + is in JSON format and can be edited directly + using a preferred file editor. +| exit | Quits interactive configuration shell mode. +|================== + +*Command Line Mode* + +Typing *nvmetcli [cmd]* on the command-line will execute a command +and not enter the interactive configuration shell. + +[] +|================== +| restore [filename.json] | Loads a saved NVMe Target configuration. + Without specifying the filename this will use + */etc/nvmet/config.json*. +| clear | Clears a current NVMe Target configuration. +| ls | Dumps the current NVMe Target configuration. +|================== + +EXAMPLES +-------- + +Make sure to run nvmetcli as root, the nvmet module is loaded, +your devices and all dependent modules are loaded, +and configfs is mounted on /sys/kernel/config +using: + + mount -t configfs none /sys/kernel/config + +The following section walks through a configuration example. + +* To get started with the interactive mode and the nvmetcli command prompt, +type (in root): +-------------- +# ./nvmetcli +...> +-------------- + +* Create a subsystem. If you do not specify a name a NQN will be generated, +which is probably the best choice. We don't do it here as the name +would be random: +-------------- +> cd /subsystems +...> create testnqn +-------------- + +* Add access for a specific NVMe Host by it's NQN: +-------------- +...> cd /hosts +...> create hostnqn +...> cd /subsystems/testnqn +...> set attr allow_any_host=0 +...> cd /subsystems/testnqn/allowed_hosts/ +...> create hostnqn +-------------- + +* Remove access of a subsystem by deleting the Host NQN: +-------------- +...> cd /subsystems/testnqn/allowed_hosts/ +...> delete hostnqn +-------------- + +* Alternatively this allows any Host to connect to the subsystsem. Only +use this in tightly controlled environments: +-------------- +...> cd /subsystems/testnqn/ +...> set attr allow_any_host=1 +-------------- + +* Create a new namespace. If you do not specify a namespace ID the fist +unused one will be used: +-------------- +...> cd /subsystems/testnqn/namespaces +...> create 1 +...> cd 1 +...> set device path=/dev/nvme0n1 +...> enable +-------------- + +Note that in the above setup the 'device_nguid' attribute +does not have to be set for correct NVMe Target functionality (but +to correctly match a namespace to the exact device upon +clear and restore operations, it is advised to set the +'device_nguid' parameter). + +* Create a loopback port that can be used with nvme-loop module +on the same physical machine... +-------------- +...> cd /ports/ +...> create 1 +...> cd 1/ +...> set addr trtype=loop +...> cd subsystems/ +...> create testnqn +-------------- + +* or create an RDMA (IB, RoCE, iWarp) port using IPv4 addressing. 4420 is the +IANA assigned default port for NVMe over Fabrics using RDMA: +-------------- +...> cd /ports/ +...> create 2 +...> cd 2/ +...> set addr trtype=rdma +...> set addr adrfam=ipv4 +...> set addr traddr=192.168.6.68 +...> set addr trsvcid=4420 +...> cd subsystems/ +...> create testnqn +-------------- + +* or create an FC port. traddr is the WWNN/WWPN of the FC port. +-------------- +...> cd /ports/ +...> create 3 +...> cd 3/ +...> set addr trtype=fc +...> set addr adrfam=fc +...> set addr traddr=nn-0x1000000044001123:pn-0x2000000055001123 +...> set addr trsvcid=none +...> cd subsystems/ +...> create testnqn +-------------- + +* Saving the NVMe Target configuration: +-------------- +./nvmetcli +...> saveconfig test.json +-------------- + +* Loading an NVMe Target configuration: +-------------- + ./nvmetcli restore test.json +-------------- + +* Clearing a current NVMe Target configuration: +-------------- + ./nvmetcli clear +-------------- + +ADDITIONAL INFORMATION +---------------------- +nvmetcli has the ability to start and stop the NVMe Target configuration +on boot and shutdown through the *systemctl* Linux utility via a .service file. +nvmetcli package comes with *nvmet.service* which when installed, it can +automatically restore the default, saved NVMe Target configuration from +*/etc/nvmet/config.json*. *nvmet.service* can be installed in directories +such as */lib/systemd/system*. + +To explicitly enable the service, type: +-------------- + systemctl enable nvmet +-------------- + +To explicitly disable the service, type: +-------------- + systemctl disable nvmet +-------------- + +See also systemctl(1). + +AUTHORS +------- +This man page was written by +mailto:james.p.freyensee@intel.com[Jay Freyensee]. nvmetcli was +originally written by mailto:hch@infradead.org[Christoph Hellwig]. + +REPORTING BUGS & DEVELOPMENT +----------------------------- +Please send patches and bug reports to linux-nvme@lists.infradead.org +for review and acceptance. + +LICENSE +------- +nvmetcli is licensed under the *Apache License, Version 2.0*. Software +distributed under this license is distributed on an "AS IS" BASIS, WITHOUT +WARRANTIES OR CONDITIONS OF ANY KIND, either expressed or implied. |