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.\" nvd driver man page.
.\"
.\" Author: Jim Harris <jimharris@FreeBSD.org>
.\"
.\" $FreeBSD: head/share/man/man4/nvd.4 301589 2016-06-08 08:50:35Z trasz $
.\"
.Dd January 28, 2016
.Dt NVD 4
.Os
.Sh NAME
.Nm nvd
.Nd NVM Express disk driver
.Sh SYNOPSIS
To compile this driver into your kernel,
place the following lines in your kernel configuration file:
.Bd -ragged -offset indent
.Cd "device nvme"
.Cd "device nvd"
.Ed
.Pp
Or, to load the driver as a module at boot, place the following lines in
.Xr loader.conf 5 :
.Bd -literal -offset indent
nvme_load="YES"
nvd_load="YES"
.Ed
.Sh DESCRIPTION
The
.Nm
driver exposes NVM Express (NVMe) namespaces as disks to the kernel disk
storage API.
It depends on the
.Xr nvme 4
driver for notification of existing NVMe namespaces and submission of NVM
I/O commands.
.Pp
Device nodes from the
.Nm
driver will have the format /dev/nvdX and are
.Xr GEOM 4
disks which can be partitioned by
.Xr geom 8 .
Note that device nodes from the
.Xr nvme 4
driver are not
.Xr GEOM 4
disks and cannot be partitioned.
.Sh CONFIGURATION
The
.Nm
driver defines a system-wide maximum delete size for NVMe devices.
The default is 1GB.
To select a different value, set the following tunable in
.Xr loader.conf 5 :
.Bd -literal -offset indent
hw.nvd.delete_max=<delete size in bytes>
.Ed
.Sh SEE ALSO
.Xr GEOM 4 ,
.Xr nvme 4 ,
.Xr geom 8 ,
.Xr nvmecontrol 8 ,
.Xr disk 9
.Sh HISTORY
The
.Nm
driver first appeared in
.Fx 9.2 .
.Sh AUTHORS
.An -nosplit
The
.Nm
driver was developed by Intel and originally written by
.An Jim Harris Aq Mt jimharris@FreeBSD.org ,
with contributions from Joe Golio at EMC.
.Pp
This man page was written by
.An Jim Harris Aq Mt jimharris@FreeBSD.org .