Create a VM layer

Before you begin, design your layers:

You cannot rename a layer when there are deployed VMs in the layer
You cannot move a deployed VM into a layer with a VM deployed on the same hypervisor

To create a layer:

Go to myCloud → Virtual datacenters
Open a virtual appliance and go to Virtual machines
From the options menu, select Add a layer
Enter the Name
Add VMs to the layer

Layers ensure that VMs deploy on separate hypervisors, so the following rules apply:

Layer type	Rules
New layer	You can add any VM to a new layer
Layer with deployed VMs	You can add a VM that is not deployed You can add a powered-off VM if it deployed on a different hypervisor from the other VMs in the layer
Different layer	You cannot move a deployed VM directly to a different layer. First, power off the VM and remove the VM from the old layer, then delete the old layer. Now you will be able to add the VM to a different layer.

Web stack use case for layers

The following diagram shows a possible anti-affinity layers use case of a simple web stack.

Diagram of an application using layers for web and database servers

In Abiquo, you could deploy this configuration as follows:

ApplicationServers layer: Tomcat1, Tomcat2
DatabaseServers layer: Database1, Database2

VMs not in layers: Apache server(s), firewall, load balancer

If the deploy of a virtual appliances with layers fails, it may be because there are not enough physical machines available in your virtual datacenter. Or some physical machines may be reserved for specific enterprises, for example. Check with your system administrator.