I decided to write this blog (read it in reference to my slideshow) to give you guidance on the complex terminologies of VMware vCloud director. I will refer to it vCD from now on to save my poor fingers.
If you’re a vSphere admin, vCD terminology is very different, it uses new terms to label layers, a way to image this is an onion ring, as you peel away the layers you get to the core or centre of the onion, vCD is abstraction layer above your infrastructure. It hides all the bits and pieces your users don’t need to see, and you don’t want them to mess around with!
Massimo gave a great quote. Check out his blog for all things vCD. He wraps it up in this quote.
“Think about how difficult it is to implement something that allows and end-user to create, in self-service mode, separate layer 2 network segments, define custom layer 3 IP policies, configure services such as DHCP, NAT and Firewall… all without having to ask the vSphere / cloud administrator to do all that for you, all without messing up with the cloud-wide setup, all without causing conflicts with the other tenants on the cloud. This is a titanic effort, believe me.”
This blog will not go through the install of vCD, as it is beyond the scope of this article, but have a look over at Kendrick Coleman’s blog site, as he has a fantastic walkthrough on a vCD install. Now let’s tackle the terminology you need to understand, these terms are prompted by the wizard once installation has completed and you’re ready to create your first tenant.
So as my vCD slide outlines, what is vCloud Director, it’s the wrapper around your vSphere infrastructure, it hides the complex bits and automates creation of VM’s and networks without admin intervention.
What is a vCD Cell?
An instance of vCloud Director
Can be scaled by adding multiple cells behind a load balancer
Scales up to 10,000 VMs and 25 vCenter Servers
Creates virtual datacentres by pooling resources into new units of consumption
Secures and Isolates users with vShield, LDAP and RBAC with policies
Components of a vCD Deployment
Min 2xESXi hosts vSphere ENT or ENT+
No Enterprise Plus licence means No vCDNI networking
Shared Storage for DRS of hosts
vCloud Director (VM)
Embedded or remote DB
AD / LDAP Directory
vShield Manager VM
vShield Edge VMs (automatically deployed on ESXi hosts)
vApps, deployed on ESXi hosts
Meter the consumption of VM’s, networks etc., and bill them.
Connect Private Clouds to public, makes the interchange of VMs across clouds seamless.
vCD Logical Terminology:
Provider virtual Data Centre (PvDC): A logical grouping of vSphere compute and storage resources where all resources are equal (some clouds may have tiers with platinum/gold/silver)
Organisation: A unit of administration with its own users, groups, policies, and catalogues. An Org has its own security boundary. These are ‘tenants’.
Organisation vDC: A logical grouping of resources from one of more provider vDCs, enabling different performance, SLA, and cost options to be available in the same organisation.
Allocate at least one vCloud Director (Cell) for each vCenter server
Configure the vCloud Director database, VMware appliance is for testing purposes and uses embedded Oracle DB, not for production (16GB Ram, 100GB Storage, 4vCpus)
Read the vCat documentation to see how See VMware recommends building vCloud Director.
Create 2 Clusters, 1 for management and 1 for resource, you don’t want your new cloud to be consuming resources before you have even installed any tenants onto it yet would you?
Create all the VMs needed for management in the management cluster.
Layers of Networking
Customer/Tenant/Organisation Network Layer (Completely Dynamic – No configuration by the customer)
vCloud Director Network Layer
Maps to components of vSphere layer and physical layer
vSphere Network Layer
vSwitches, Port Groups etc. (must be stable and static)
Physical Network Layer
Switches/routers and IP’s etc. (must be stable and static)
vCD Networking Terms:
The vCD inner networking component is called External Networks. If you want your Organization (and in turns your vApps) to have connectivity to the external world you need to have External Networks. As the word implies, these are networks that are managed by someone that is typically external to the vCD environment and are identified by a vSphere Port Group. That’s in fact what you do when you create a vCD External Network: you point to an existing vSphere Port Group. Essentially you are telling vCloud Director that there is a Port Group that is able to provide external connectivity to your cloud environment. The typical example is a Port Group with VLAN 233 (for instance) which can support native Internet traffic. For naming convention you will be calling this External Network something like Internet or Ext-Net-Internet. I usually suggest naming the vCD External Network after the vSphere Port Group for ease of tracking.
• Connects vCD to the outside world
• Based on a vSphere port group
When you create the port group on the dvSwitch recommended editing settings to make the ports Ephemeral – no limit on ports
External Networks are easy. With Organization Networks things start to become more “interesting”. In the previous section we have created cloud-wide external connectivity (i.e. External Networks). Now we are zooming inside an Organization. An Organization (or Org) is a logical construct within vCD that describes a tenant or a customer. Cloud end-users are defined inside each Organization.
• A virtual network for tenants / customers
• Communicate with each other and access the internet
• Require an External network, network pool or both
The 3 Types of Org network a tenant can have are:
• External Organisational network: Direct
• External Organisational network: NAT-routed
• Internal Organisational network (private)
3 types of network pools you can allocate to tenants:
VLAN Backed (flexible, no special MTU settings, requires a lot of VLAN management)
Network Isolation Backed (vCDNI – no VLAN ranges to track, must change MTU / mac-in-mac encapsulation)
vSphere Port Group Backed (Standard and Distributed, no auto network deployment – most work involved)
Ideally you need to use vCDNI, so everything is automated, but you will need an Enterprise Plus licence for this feature, and also make sure that the MTU settings are set higher than 1500 at the physical switch level, esx host level and vCenter server level. You can use as high as 9000 without causing problems.
At this point you may have an overall understanding of what a Network Pool is and why it is used. In summary it is a small CMDB that contains layer 2 segments available to vCD administrators and end-users. Note Network Pools need to be created before we start deploying the actual networks we have described above (with the exception of the External Networks because they don’t use Networks Pools).
So far we kept referring to a “layer 2 segment” as a Port Group with an associated VLAN id. This is correct but it doesn’t tell the whole story. There are really three different types of Network Pools one can create.
VLAN-backed Network Pools: this is the easiest to get. You can, for example, create a Network Pool and give it a range of VLAN ID 100 to 199. Whenever you grab one of these IDs because you need to deploy a new layer 2 segment, vCD will tell vCenter “please create on the fly a Port Group, and give it VLAN ID 100″. The next time there is a need for another layer 2 segment vCD will tell vCenter “please create on the fly a Port Group, and give it VLAN ID 101″. And so on. Of course if one of these networks is destroyed during the lifecycle of the cloud, the corresponding VLAN ID gets put back into the pool of available networks to be deployed.
Port Group-backed Network Pools: it is similar to the VLAN-backed. The difference is that the Port Groups need to be pre-provisioned on the vSphere infrastructure and they need to be imported into vCloud Director. So vCD won’t tell vCenter to create these on the fly, they are already there pre-provisioned. Why using this? Well there are some circumstances where vCenter cannot easily (programmatically) create Port Groups on the fly. This is the case when you use vSphere Standard Switches (as opposed to Distributed Switches) or when you use the Nexus 1000v (at the moment vCD cannot manipulate programmatically Port Profiles).
vCloud Director Network Isolation Network Pools: This is when things start to get interesting (again). We use a technique called Mac-in-Mac to create layer 2 separated networks without using VLANs. Yeah that’s right. This is extremely useful for big environments where VLAN management is problematic, either because there is a limited number of VLANs available or because keeping track of VLANs is a big management overhead (especially if you use an excel spread sheet to do that ).
When you create such a Network Pool you only specify how many of these layer 2 networks you want this Network Pool to have and you are done. When vCD starts to deploy Port Groups from this Network Pool you won’t see any VLAN associated to them but they are indeed different layer 2 segments.
Now the acronym VCD-NI and the labels Preprovisioned and Created-on-the-fly in the pictures above should make more sense to you. Try to go back and have a look at them again.
Virtual Machines IP management
First of all note you cannot connect a vNIC to an External Network directly. You can however connect the vNIC to either an Organization Network or a vApp Network.
Now the question is: what happens when you connect a vNIC to either an Organization Network or a vApp Network? How do you control the layer 3 behaviour? As we said, you have a choice of connecting each vNIC of the VM to an Organization Network, a vApp Network or leave the vNIC not connected.
Duncan Epping – Creating a vCD Lab on your Mac/Laptop
Chris Colotti – VMware vCloud “In a Box” for your Home Lab
vCloud networking explained in 1 slide and 52 animations