Increase reserved memory for computes when enabling DVR

This patch adds an example increased value for NovaReservedHostMemory
and some documentation around tuning this value when DVR is enabled.

Closes-Bug: #1630583

Change-Id: I2718d72d307a1c90061606e5f36c96f964cd2fb5

diff --git a/environments/neutron-ovs-dvr.yaml b/environments/neutron-ovs-dvr.yaml
index b658d3a..f4f9990 100644 (file)
--- a/environments/neutron-ovs-dvr.yaml
+++ b/environments/neutron-ovs-dvr.yaml
@@ -37,3 +37,16 @@ parameter_defaults:
   # NeutronL3HA can be returned to false. All new systems should be deployed
   # with NeutronL3HA set to false.
   NeutronL3HA: false
+
+  # Enabling DVR deploys additional services to the compute nodes that through
+  # normal operation will consume memory. The amount required is roughly
+  # proportional to the number of Neutron routers that will be scheduled to
+  # that host. It is necessary to reserve memory on the compute nodes to avoid
+  # memory issues when creating instances that are connected to routed
+  # networks. The current expected consumption is 50 MB per router in addition
+  # to the base reserved amount.  Deployers should refer to existing
+  # documentation, release notes, etc. for additional information on estimating
+  # an appropriate value. The provided value here is based on an estimate of 10
+  # routers and is an example value *only* and should be reviewed and modified
+  # if necessary before deploying.
+  NovaReservedHostMemory: 2560