From 2f9bbed3a9a3b1a541124f484ae324a809262fb5 Mon Sep 17 00:00:00 2001
From: Edward Hope-Morley <edward.hope-morley@canonical.com>
Date: Thu, 12 Jul 2018 11:27:22 +0100
Subject: [PATCH] Enable discard

By default discard/trim requests are disabled for libvirt. This
patch enables them by default although in order to actually use
them, instances still need be using scsi disk devices. Also this
patch only permits Nova storage (e.g. instance root disk) to use
discard. For Cinder volumes this must be enabled in Cinder.

Change-Id: Iceb22fe5206629bc7b4096f518b8977c2e14def3
Closes-Bug: #1781382
---
 templates/mitaka/nova.conf | 1 +
 templates/newton/nova.conf | 1 +
 templates/ocata/nova.conf  | 1 +
 templates/pike/nova.conf   | 1 +
 4 files changed, 4 insertions(+)

diff --git a/templates/mitaka/nova.conf b/templates/mitaka/nova.conf
index c43095a6..75f0e6f2 100644
--- a/templates/mitaka/nova.conf
+++ b/templates/mitaka/nova.conf
@@ -207,6 +207,7 @@ live_migration_tunnelled = False
 {% if use_multipath -%}
 iscsi_use_multipath = {{ use_multipath }}
 {% endif %}
+hw_disk_discard = unmap
 
 {% if virt_type == 'lxd' -%}
 [lxd]
diff --git a/templates/newton/nova.conf b/templates/newton/nova.conf
index e57fb1d1..1c951b52 100644
--- a/templates/newton/nova.conf
+++ b/templates/newton/nova.conf
@@ -207,6 +207,7 @@ live_migration_tunnelled = False
 {% if use_multipath -%}
 volume_use_multipath = {{ use_multipath }}
 {% endif %}
+hw_disk_discard = unmap
 
 {% if virt_type == 'lxd' -%}
 [lxd]
diff --git a/templates/ocata/nova.conf b/templates/ocata/nova.conf
index 5d98d8c7..eb6ea723 100644
--- a/templates/ocata/nova.conf
+++ b/templates/ocata/nova.conf
@@ -208,6 +208,7 @@ live_migration_tunnelled = False
 {% if use_multipath -%}
 volume_use_multipath = {{ use_multipath }}
 {% endif %}
+hw_disk_discard = unmap
 
 {% if virt_type == 'lxd' -%}
 [lxd]
diff --git a/templates/pike/nova.conf b/templates/pike/nova.conf
index 067728f1..975a261d 100644
--- a/templates/pike/nova.conf
+++ b/templates/pike/nova.conf
@@ -211,6 +211,7 @@ live_migration_tunnelled = False
 {% if use_multipath -%}
 volume_use_multipath = {{ use_multipath }}
 {% endif %}
+hw_disk_discard = unmap
 
 {% if virt_type == 'lxd' -%}
 [lxd]