svn commit: r360396 - head/release/tools

[Colin Percival]

Author: cperciva
Date: Mon Apr 27 21:44:02 2020
New Revision: 360396
URL: https://svnweb.freebsd.org/changeset/base/360396

Log:
  Set use_nvd=0 in EC2 AMIs.
  
  FreeBSD is in the process of switching from nvd(4) to nda(4) as the disk
  device front-end to NVMe. Changing the default in the kernel is tricky
  since existing systems may have /dev/nvd* hard-coded e.g. in /etc/fstab;
  however, there's no reason to not change the default in HEAD for *new*
  systems.
  
  At present I have no intention of MFCing this to stable branches, since
  someone might reasonably expect scripts they use for launching and
  configuring FreeBSD 12.1 instances to work with FreeBSD 12.2 AMIs, for
  example.
  
  Reviewed by:	gjb, imp
  Relnotes:	NVMe disks in EC2 instances launched from 13.0 and later
  		now show up as nda(4) devices.
  Differential Revision:	https://reviews.freebsd.org/D24583

Modified:
  head/release/tools/ec2.conf

Modified: head/release/tools/ec2.conf
==============================================================================
--- head/release/tools/ec2.conf	Mon Apr 27 21:41:00 2020	(r360395)
+++ head/release/tools/ec2.conf	Mon Apr 27 21:44:02 2020	(r360396)
@@ -98,6 +98,10 @@ vm_extra_pre_umount() {
 	# Load the kernel module for the Amazon "Elastic Network Adapter"
 	echo 'if_ena_load="YES"' >> ${DESTDIR}/boot/loader.conf
 
+	# Use the "nda" driver for accessing NVMe disks rather than the
+	# historical "nvd" driver.
+	echo 'hw.nvme.use_nvd="0"' >> ${DESTDIR}/boot/loader.conf
+
 	# Disable ChallengeResponseAuthentication according to EC2
 	# requirements.
 	sed -i '' -e \