VMware Cloud Foundation 4 presents an important step in offering a hybrid cloud platform supporting native Kubernetes workloads and management alongside your traditional VM-based workloads.
Cloud Foundation has an automated deployment process, known as Bring-up which deploys standardized workload ready private cloud in just matter of hours! By any measure, VMware Cloud Foundation 4 is a massive release that delivers a complete full stack for all capabilities required, more than I can cover in a single blog. Hence presenting a series where we would look at in-depth concepts of VCF 4.
VCF 4 Architecture
Before we understand the Architecture, check out the software Building blocks of VCF 4.0:
The new version of VCF 4.0 includes vSphere 7.0, VSAN 7.0, NSX-T 3.0, VRA 8.1, vRLCM 8.1 as well as SDDC manager to manage your virtual infrastructure domains. You can find detailed information on Cloud Foundation Bill of Materials (BOM) here. One thing to note here is you cannot upgrade from VCF 3.x to VCF 4.x. VCF 4 has to be deployed as ‘Greenfield’ deployment only, however this functionality is being currently worked upon and we can expect direct upgrade in coming releases.
Workload Domain
Workload domain is purpose built logical SDDC instance of one or more vsphere cluster with dedicated vcenter server and dedicated or shared NSX-T instance. It also includes dedicated vSAN Ready nodes. It has automated provisioning and can support up to 15 workload domains.
Most of the customers have question about how many vCenter Server licenses are required during deployment. So to answer this question, you only need single vcenter Server License which is entered during initial deployment and that will support all the vcenter instances deployed within the VCF.
Management Domain
It a special purpose domain that is automatically deployed during Initial Deployment (which is also called as Bring-Up process). It requires minimum 4 hosts and vSAN Storage. vSAN is the only principal storage option for Management Domain.
Management domain is designed to host all infrastructure components like SDDC manager, vcenter server and NSX-T instances and NSX edge instances. It also supports 3rd party management apps like Backup server, Active Directory Servers, Domain controllers, etc.
So, now Management Domain in VCF 4 has smaller footprint as it contains smaller number of VMs. This is because PSCs are now Embedded (External PSC’s are not supported) and NSX Managers and Controllers are integrated into one!
Since the PSC’s are embedded, the functionality of SDDC manager towards has also changed. As new vCenters are deployed, SDDC manager configures a replication ring topology for all the embedded PSC’s and SDDC Manager authenticates to the ring rather than to individual PSCs!
Virtual Infrastructure (VI) Workload Domain
VI Workload Domain contains one or more sphere infrastructures designed to run Customer’s applications and has a dedicated vcenter server deployed in the management Domain.
While deploying the VI workload Domain, Admins have an option of deploying a NSX instance or sharing an NSX instance with existing VI workload domain. Admins also have option to choose between vSAN, NFS or FC as their principal storage options unlike the management domain where vSAN is the only principal storage used.
For the first VI workload domain, the workflow deploys a cluster of three NSX Managers in the management domain and configures a virtual IP (VIP) address for the NSX Manager cluster. Subsequent VI workload domains can share an existing NSX Manager cluster or deploy a new one as stated above.
The management domain and deployed VI workload domains are logical units that carve up the compute, network, and storage resources of the Cloud Foundation system.
VCF 4 Deployment Types
There are two deployment models used based on the size of the environment.
Consolidated Architecture :
Where customer workloads runs in Management Domain, as simple as that! This model has shared vcenter server where customer workloads are deployed into resource pools. This is recommended for small deployments and it uses minimum of 4 servers. Consolidated deployment uses vSAN as a principal storage and they don’t have any option to select any other type of storage.
Standard Architecture
The standard architecture aligns with industry best practices separating management workloads with Infrastructure workloads. This is recommended for medium to Large Deployments and it required minimum of 7 (recommended 8) servers to deploy.
Management Workloads are dedicated to Infrastructure and Dedicated VI domains for User workloads. You can run max 15 Workload domains including Management Domain. The important point to note here is vCenter Servers run in enhanced Linked-mode.
Key Takeaways
- Consolidated deployments utilize one workload domain and one vcenter server.
- Standard deployments use separate vCenter server for each Domain.
- Multiple clusters are supported in Standard and standard architectures both.
- Stretched vSAN deployments are supported.
- Consolidated deployment uses vSAN for principal storage.
- It’s important to note that VCF 4.1 now supports vVols as Principal Storage in VCF Workload Domains to deliver greater flexibility and storage options.
- Each Workload domain can consist of multiple clusters and can scale up to VMware documented maximums!
- More information on Consolidated Architecture limitations with Cloud Foundation (70622) – https://kb.vmware.com/s/article/70622
Jatin Purohit 
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