Create a VM layer

Before you begin, design your layers:

You cannot rename a layer when there are deployed VMs in the layer. You will need to move the VMs to another layer with a new name
You may be able to move a powered off VM in a way that could break the anti-affinity rules, but vCenter may prevent you from powering on the VM.

Privileges: Manage layers

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

Add an anti-affinity layer to a virtual appliance

Create an anti-affinity layer

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

Layer type	Rules

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 is deployed on a different hypervisor from the other VMs in the layer
Different layer	For vCenter clusters, you can power off a VM and move it to a different layer, but if the VM host is not compatible with the anti-affinity rule, then you may not be able to power on the VM. For vCenter hosts, you cannot move a deployed VM directly to a different layer. First, power off the VM and remove the VM from 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.

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.