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.Dd December 20, 2017
.Dt NDA 4
.Os
.Sh NAME
.Nm nda
.Nd NVMe Direct Access device driver
.Sh SYNOPSIS
.Cd device nvme
.Cd device scbus
.Sh DESCRIPTION
The
.Nm
driver provides support for direct access devices, implementing the
.Tn NVMe
command protocol, that are attached to the system through a host adapter
supported by the CAM subsystem.
.Sh SYSCTL VARIABLES
The following variables are available as both
.Xr sysctl 8
variables and
.Xr loader 8
tunables:
.Bl -tag -width 12
.It Va kern.cam.nda.sort_io_queue
.Pp
This variable determines whether the software queued entries are
sorted in LBA order or not.
Sorting is almost always a waste of time.
The default is to not sort.
.El
.Pp
The following report per-device settings, and are read-only unless
otherwise indicated. Replace
.Va N
with the device unit number.
.Bl -tag -width 12
.It Va kern.cam.nda.N.rotating
.Pp
This variable reports whether the storage volume is spinning or
flash.
It's value is hard coded to 0 indicating flash.
.It Va kern.cam.nda.N.unmapped_io
This variable reports whether the
.Nm
driver accepts unmapped I/O for this unit.
.Sh FILES
.Bl -tag -width ".Pa /dev/nda*" -compact
.It Pa /dev/nda*
NVMe storage device nodes
.El
.Sh SEE ALSO
.Xr nvme 4 ,
.Xr nvd 4
.Sh HISTORY
The
.Nm
driver first appeared in
.Fx 12.0 .
.Sh AUTHORS
.An Warner Losh Aq Mt imp@FreeBSD.org