Move Disk allocation ratio to ResourceTracker

We already moved the CPU and RAM ratios to the compute nodes in Liberty
but we forgot to add the disk one. Adding it now.

That change specifically implies that nova.conf is consistent across the whole
cloud since what was formerly defined on the scheduler side will have its
definition by the compute nodes.

Co-Authored-By: Sylvain Bauza <sbauza@redhat.com>
UpgradeImpact

Change-Id: Id4b44dc4c3391563154a30406a5f1e7a2dc015b3
Partially-Implements: blueprint disk-allocation-ratio-to-rt

nova/compute/resource_tracker.py

@@ -81,6 +81,18 @@ allocation_ratio_opts = [
              'NOTE: This can be set per-compute, or if set to 0.0, the value '
              'set on the scheduler node(s) will be used '
              'and defaulted to 1.5'),
+    cfg.FloatOpt('disk_allocation_ratio',
+        default=1.0,
+        help='This is the virtual disk to physical disk allocation ratio used '
+             'by the disk_filter.py script to determine if a host has '
+             'sufficient disk space to fit a requested instance. A ratio '
+             'greater than 1.0 will result in over-subscription of the '
+             'available physical disk, which can be useful for more '
+             'efficiently packing instances created with images that do not '
+             'use the entire virtual disk,such as sparse or compressed '
+             'images. It can be set to a value between 0.0 and 1.0 in order '
+             'to preserve a percentage of the disk for uses other than '
+             'instances'),
 ]
 
 

nova/conf/scheduler.py

@@ -322,30 +322,6 @@ be sure to test this with your selected scheduler.
     ``nova-service service_down_time``
 """)
 
-disk_allocation_ratio_opt = cfg.FloatOpt("disk_allocation_ratio",
-        default=1.0,
-        help="""
-This is the virtual disk to physical disk allocation ratio used by the
-disk_filter.py script to determine if a host has sufficient disk space to fit a
-requested instance. A ratio greater than 1.0 will result in over-subscription
-of the available physical disk, which can be useful for more efficiently
-packing instances created with images that don't use the entire virtual disk,
-such as sparse or compressed images. It can be set to a value between 0.0 and
-1.0 in order to preserve a percentage of the disk for uses other than
-instances.
-
-This option is only used by the FilterScheduler and its subclasses; if you use
-a different scheduler, this option has no effect.
-
-* Services that use this:
-
-    ``nova-scheduler``
-
-* Related options:
-
-    None
-""")
-
 isolated_img_opt = cfg.ListOpt("isolated_images",
         default=[],
         help="""
@@ -723,7 +699,6 @@ default_opts = [host_subset_size_opt,
                driver_opt,
                driver_period_opt,
                scheduler_json_config_location_opt,
-               disk_allocation_ratio_opt,
                isolated_img_opt,
                isolated_host_opt,
                restrict_iso_host_img_opt,