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NVMF(4) Kernel Interfaces Manual NVMF(4) NAME nvmf -- NVM Express over Fabrics host driver SYNOPSIS To compile the driver into the kernel, place the following line in the kernel configuration file: device nvmf Alternatively, to load the driver as a module at boot time, place the following line in loader.conf(5): nvmf_load="YES" DESCRIPTION The nvmf driver provides the kernel component of an NVM Express over Fab- rics host. The NVMeoF host is the client which provides local access to namespaces exported by a remote controller. Associations between the local host and remote controllers are managed us- ing nvmecontrol(8). New associations are created via the connect command and destroyed via the disconnect command. If an association's connection is interrupted, the reconnect command creates a new association to replace the interrupted association. Similar to nvme(4), nvmf creates controller device nodes using the format /dev/nvmeX and namespace device nodes using the format /dev/nvmeXnsY. nvmf also exports remote namespaces via the CAM nda(4) peripheral driver. Un- like nvme(4), nvmf does not support the nvd(4) disk driver. Associations require a supported transport such as nvmf_tcp(4) for associa- tions using TCP/IP. SYSCTL VARIABLES The following variables are available as both sysctl(8) variables and loader(8) tunables: kern.nvmf.fail_on_disconnection Determines the behavior when an association's connection is inter- rupted. By default, input/output operations are suspended while a host is disconnected. This includes operations pending at the time the association's connection was interrupted as well as new re- quests submitted while the host is disconnected. Once a new asso- ciation is established, suspended I/O requests are retried. When set to 1, input/output operations fail with EIO while a host is disconnected and nda(4) peripherals are destroyed after the first failed I/O request. Note that any destroyed nda(4) peripherals will be recreated after a new association is established. SEE ALSO nda(4), nvme(4), nvmf_tcp(4), nvmft(4), nvmecontrol(8) HISTORY The nvmf module first appeared in FreeBSD 15.0. AUTHORS The nvmf driver was developed by John Baldwin <jhb@FreeBSD.org> under spon- sorship from Chelsio Communications, Inc. FreeBSD ports 15.quarterly May 7, 2025 NVMF(4)
NAME | SYNOPSIS | DESCRIPTION | SYSCTL VARIABLES | SEE ALSO | HISTORY | AUTHORS
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