[Disk] Added parametrization of disk_allocation_ratio.

Change-Id: Icc734e213bf4f3f94defc7b10f68914cfa86a3b6
diff --git a/metadata/service/control/single.yml b/metadata/service/control/single.yml
index a153e31..1f45b14 100644
--- a/metadata/service/control/single.yml
+++ b/metadata/service/control/single.yml
@@ -17,6 +17,7 @@
       scheduler_default_filters: "DifferentHostFilter,RetryFilter,AvailabilityZoneFilter,RamFilter,CoreFilter,DiskFilter,ComputeFilter,ComputeCapabilitiesFilter,ImagePropertiesFilter,ServerGroupAntiAffinityFilter,ServerGroupAffinityFilter"
       cpu_allocation_ratio: 16.0
       ram_allocation_ratio: 1.5
+      disk_allocation_ratio: 1.0
       logging:
       - engine: syslog
         facility: local0