OpenStack compact cloud

OpenStack compact cloud

The Compact Cloud is an OpenStack-based reference architecture for MCP. It is designed to provide a generic public cloud user experience to the cloud tenants in terms of available virtual infrastructure capabilities and expectations. It features reduced control plane footprint, at the cost of reduced maximum capacity.

The compact reference architecture is designed to support up to 500 virtual servers or 50 hypervisor hosts. In addition to the desirable number of hypervisors, 3 infrastructure physical servers are required for the control plane. These 3 servers host the OpenStack virtualized control plane (VCP), StackLight services, and virtual Neutron gateway nodes.


Out of the box, the compact reference architecture supports only Neutron OVS networking for OpenStack. DVR is enabled by default.

OpenContrail is not supported out of the box in the compact reference architecture.

The following diagram describes the distribution of VCP and other services throughout the infrastructure nodes.


The following table describes the hardware nodes in the CPI reference architecture, roles assigned to them, and the number of nodes of each type.

Physical servers for MCP
Node type Role name Number of servers
Infrastructure nodes (VCP) kvm 3
OpenStack compute nodes cmp up to 50
Staging infrastructure nodes kvm 3
Staging compute nodes cmp 2 - 5

The following table summarizes the VCP virtual machines mapped to physical servers.

Resource requirements per VCP and DriveTrain roles
Virtual server roles Physical servers # of instances CPU vCores per instance Memory (GB) per instance Disk space (GB) per instance
ctl kvm01 kvm02 kvm03 3 8 32 100
msg kvm01 kvm02 kvm03 3 8 32 100
dbs kvm01 kvm02 kvm03 3 8 16 100
prx kvm02 kvm03 2 4 8 50
cfg kvm01 1 2 8 50
mon kvm01 kvm02 kvm03 3 4 16 500
mtr kvm01 kvm02 kvm03 3 4 32 1000
log kvm01 kvm02 kvm03 3 4 32 2000
cid kvm01 kvm02 kvm03 3 8 32 100
gtw kvm01 kvm02 kvm03 3 4 16 50
mdb kvm01 kvm02 kvm03 3 4 8 150
TOTAL   30 166 672 12450


  • The gtw VM should have four separate NICs for the following interfaces: dhcp, primary, tenant, and external. It simplifies the host networking as you do not need to pass VLANs to VMs.
  • The prx VM should have an additional NIC for the proxy network.
  • All other nodes should have two NICs for DHCP and primary networks.

See also