1.\" 2.\" Copyright (c) 2017 Netflix, Inc. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 10.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" notice, this list of conditions and the following disclaimer in the 12.\" documentation and/or other materials provided with the distribution. 13.\" 14.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24.\" SUCH DAMAGE. 25.\" 26.\" $FreeBSD$ 27.\" 28.Dd December 20, 2017 29.Dt NDA 4 30.Os 31.Sh NAME 32.Nm nda 33.Nd NVMe Direct Access device driver 34.Sh SYNOPSIS 35.Cd device nvme 36.Cd device scbus 37.Sh DESCRIPTION 38The 39.Nm 40driver provides support for direct access devices, implementing the 41.Tn NVMe 42command protocol, that are attached to the system through a host adapter 43supported by the CAM subsystem. 44.Sh SYSCTL VARIABLES 45The following variables are available as both 46.Xr sysctl 8 47variables and 48.Xr loader 8 49tunables: 50.Bl -tag -width 12 51.It Va kern.cam.nda.sort_io_queue 52.Pp 53This variable determines whether the software queued entries are 54sorted in LBA order or not. 55Sorting is almost always a waste of time. 56The default is to not sort. 57.El 58.Pp 59The following report per-device settings, and are read-only unless 60otherwise indicated. Replace 61.Va N 62with the device unit number. 63.Bl -tag -width 12 64.It Va kern.cam.nda.N.rotating 65.Pp 66This variable reports whether the storage volume is spinning or 67flash. 68It's value is hard coded to 0 indicating flash. 69.It Va kern.cam.nda.N.unmapped_io 70This variable reports whether the 71.Nm 72driver accepts unmapped I/O for this unit. 73.El 74.Sh FILES 75.Bl -tag -width ".Pa /dev/nda*" -compact 76.It Pa /dev/nda* 77NVMe storage device nodes 78.El 79.Sh SEE ALSO 80.Xr nvd 4 , 81.Xr nvme 4 82.Sh HISTORY 83The 84.Nm 85driver first appeared in 86.Fx 12.0 . 87.Sh AUTHORS 88.An Warner Losh Aq Mt imp@FreeBSD.org 89