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]