Azure VMware Solution private cloud and cluster concepts

Azure VMware Solution provides VMware-based private clouds in Azure. The private cloud hardware and software deployments are fully integrated and automated in Azure. Deploy and manage the private cloud through the Azure portal, CLI, or PowerShell.

A private cloud includes clusters with:

• Dedicated bare-metal server hosts provisioned with VMware ESXi hypervisor
• VMware vCenter Server for managing ESXi and vSAN
• VMware NSX software-defined networking for vSphere workload VMs
• VMware vSAN datastore for vSphere workload VMs
• VMware HCX for workload mobility
• Resources in the Azure underlay (required for connectivity and to operate the private cloud)

Private clouds are installed and managed within an Azure subscription. The number of private clouds within a subscription is scalable. Initially, there's a limit of one private cloud per subscription. There's a logical relationship between Azure subscriptions, Azure VMware Solution private clouds, vSAN clusters, and hosts.

The following diagram describes the architectural components of the Azure VMware Solution.

Each Azure VMware Solution architectural component has the following function:

• Azure Subscription: Provides controlled access, budget, and quota management for the Azure VMware Solution.
• Azure Region: Groups data centers into Availability Zones (AZs) and then groups AZs into regions.
• Azure Resource Group: Places Azure services and resources into logical groups.
• Azure VMware Solution Private Cloud: Offers compute, networking, and storage resources using VMware software, including vCenter Server, NSX software-defined networking, vSAN software-defined storage, and Azure bare-metal ESXi hosts. Azure NetApp Files, Azure Elastic SAN, and Pure Cloud Block Store are also supported.
• Azure VMware Solution Resource Cluster: Provides compute, networking, and storage resources for customer workloads by scaling out the Azure VMware Solution private cloud using VMware software, including vSAN software-defined storage and Azure bare-metal ESXi hosts. Azure NetApp Files, Azure Elastic SAN, and Pure Cloud Block Store are also supported.
• VMware HCX: Delivers mobility, migration, and network extension services.
• VMware Site Recovery: Automates disaster recovery and storage replication services with VMware vSphere Replication. Third-party disaster recovery solutions Zerto Disaster Recovery and JetStream Software Disaster Recovery are also supported.
• Dedicated Microsoft Enterprise Edge (D-MSEE): Router that connects Azure cloud and the Azure VMware Solution private cloud instance.
• Azure Virtual Network (VNet): Connects Azure services and resources together.
• Azure Route Server: Exchanges dynamic route information with Azure networks.
• Azure Virtual Network Gateway: Connects Azure services and resources to other private networks using IPSec VPN, ExpressRoute, and VNet to VNet.
• Azure ExpressRoute: Provides high-speed private connections between Azure data centers and on-premises or colocation infrastructure.
• Azure Virtual WAN (vWAN): Combines networking, security, and routing functions into a single unified Wide Area Network (WAN).

Hosts

Azure VMware Solution clusters are based upon hyper-converged infrastructure. The following table shows the CPU, memory, disk and network specifications of the host.

An Azure VMware Solution cluster requires a minimum number of three hosts. You can only use hosts of the same type in a single Azure VMware Solution private cloud. Hosts used to build or scale clusters come from an isolated pool of hosts. Those hosts passed hardware tests and had all data securely deleted before being added to a cluster.

All the above Host Types have 100 Gbps network interface throughput.

(*) details available via the Azure pricing calculator.

(**) AV64 Prerequisite: An Azure VMware Solution private cloud deployed with AV36, AV36P, or AV52 is required prior to adding AV64.

Azure Region Availability Zone (AZ) to SKU mapping table

When planning your Azure VMware Solution design, use the following table to understand what SKUs are available in each physical Availability Zone of an Azure region.

The Multi-AZ capability for Azure VMware Solution Stretched Clusters is also tagged in the following table. Customer quota for Azure VMware Solution is assigned by Azure region, and you are not able to specify the Availability Zone during private cloud provisioning. An auto selection algorithm is used to balance deployments across the Azure region. If you have a particular Availability Zone you want to deploy to, open a Service Request with Microsoft requesting a "special placement policy" for your subscription, Azure region, Availability Zone, and SKU type. This policy remains in place until you request it be removed or changed.

SKUs marked in bold are of limited availability due to customer consumption and quota may not be available upon request. The AV64 SKU should be used instead when AV36, AV36P, or AV52 SKUs are limited.

AV64 SKUs are available per Availability Zone, the table below lists the Azure regions that support this SKU. For RAID-6 FTT2 and RAID-1 FTT3 storage policies, six and seven Fault Domains (FDs) are needed respectively, the FD count for each Azure region is listed in the "AV64 FDs Supported" column.

Clusters

For each private cloud created, there's one vSAN cluster by default. You can add, delete, and scale clusters. The minimum number of hosts per cluster and the initial deployment is three.

You use vCenter Server and NSX Manager to manage most aspects of cluster configuration and operation. All local storage of each host in a cluster is under the control of VMware vSAN.

The Azure VMware Solution management and control plane have the following resource requirements that need to be accounted for during solution sizing of a standard private cloud.

The Azure VMware Solution management and control plane have the following resource requirements that need to be accounted for during solution sizing of a stretched clusters private cloud. VMware SRM isn't included in the table since it currently isn't supported.

These resource requirements only apply to the first cluster deployed in an Azure VMware Solution private cloud. Subsequent clusters only need to account for the vSphere Cluster Service, ESXi resource requirements and vSAN System Usage in solution sizing.

The virtual appliance Typical Raw vSAN Datastore Usage values account for the space occupied by virtual machine files, including configuration and log files, snapshots, virtual disks and swap files.

The VMware ESXi nodes have compute usage values that account for the vSphere VMkernel hypervisor overhead, vSAN overhead and NSX distributed router, firewall and bridging overhead. These are estimates for a standard three cluster configuration. The storage requirements are listed as not applicable (N/A) since a boot volume separate from the vSAN Datastore is used.

The VMware vSAN System Usage storage overhead accounts for vSAN performance management objects, vSAN file system overhead, vSAN checksum overhead and vSAN deduplication and compression overhead. To view this consumption, select the Monitor, vSAN Capacity object for the vSphere Cluster in the vSphere Client.

The VMware HCX and VMware Site Recovery Manager resource requirements are optional Add-ons to the Azure VMware Solution service. Discount these requirements in the solution sizing if they aren't being used.

The VMware Site Recovery Manager Add-On has the option of configuring multiple VMware vSphere Replication Server Appliances. The previous table assumes one vSphere Replication Server appliance is used.

Sizing an Azure VMware Solution is an estimate; the sizing calculations from the design phase should be validated during the testing phase of a project to ensure the Azure VMware Solution is sized correctly for the application workload.

The following table describes the maximum limits for Azure VMware Solution.

* For information about Recovery Point Objective (RPO) lower than 15 minutes, see How the 5 Minute Recovery Point Objective Works in the vSphere Replication Administration guide.

For other VMware-specific limits, use the VMware configuration maximum tool.

VMware software versions

Microsoft is a member of the VMware Metal-as-a-Service (MaaS) program and uses the VMware Cloud Provider Stack (VCPS) for Azure VMware Solution upgrade planning.

The VMware solution software versions used in new deployments of Azure VMware Solution private clouds are:

The current running software version is applied to new clusters added to an existing private cloud.

Host maintenance and lifecycle management

One benefit of Azure VMware Solution private clouds is that the platform is maintained for you. Microsoft is responsible for the lifecycle management of VMware software (ESXi, vCenter Server, and vSAN) and NSX appliances. Microsoft is also responsible for bootstrapping the network configuration, like creating the Tier-0 gateway and enabling North-South routing. You’re responsible for the NSX SDN configuration: network segments, distributed firewall rules, Tier 1 gateways, and load balancers.

Microsoft is responsible for applying any patches, updates, or upgrades to ESXi, vCenter Server, vSAN, and NSX in your private cloud. The impact of patches, updates, and upgrades on ESXi, vCenter Server, and NSX has the following considerations:

• ESXi - There's no impact to workloads running in your private cloud. Access to vCenter Server and NSX isn't blocked during this time. During this time, we recommend you don't plan other activities like: scaling up private cloud, scheduling or initiating active HCX migrations, making HCX configuration changes, and so on, in your private cloud.

• vCenter Server - There's no impact to workloads running in your private cloud. During this time, vCenter Server is unavailable and you can't manage VMs (stop, start, create, or delete). We recommend you don't plan other activities like scaling up private cloud, creating new networks, and so on, in your private cloud. When you use VMware Site Recovery Manager or vSphere Replication user interfaces, we recommend you don't do either of the actions: configure vSphere Replication, and configure or execute site recovery plans during the vCenter Server upgrade.

• NSX - The workload is impacted. When a particular host is being upgraded, the VMs on that host might lose connectivity from 2 seconds to 1 minute with any of the following symptoms:

  • Ping errors

  • Packet loss

  • Error messages (for example, Destination Host Unreachable and Net unreachable)

  During this upgrade window, all access to the NSX management plane is blocked. You can't make configuration changes to the NSX environment for the duration. Your workloads continue to run as normal, subject to the upgrade impact previously detailed.

  During the upgrade time, we recommend you don't plan other activities like, scaling up private cloud, and so on, in your private cloud. Other activities can prevent the upgrade from starting or could have adverse impacts on the upgrade and the environment.

You're notified through Azure Service Health that includes the timeline of the upgrade. This notification also provides details on the upgraded component, its effect on workloads, private cloud access, and other Azure services. You can reschedule an upgrade as needed.

Software updates include:

• Patches - Security patches or bug fixes released by VMware

• Updates - Minor version change of a VMware stack component

• Upgrades - Major version change of a VMware stack component

Documented VMware workarounds are implemented in lieu of installing a corresponding patch until the next scheduled updates are deployed.

Host monitoring and remediation

Azure VMware Solution continuously monitors the health of both the VMware components and underlay. When Azure VMware Solution detects a failure, it takes action to repair the failed components. When Azure VMware Solution detects a degradation or failure on an Azure VMware Solution node, it triggers the host remediation process.

Host remediation involves replacing the faulty node with a new healthy node in the cluster. Then, when possible, the faulty host is placed in VMware vSphere maintenance mode. VMware vSphere vMotion moves the VMs off the faulty host to other available servers in the cluster, potentially allowing zero downtime for live migration of workloads. If the faulty host can't be placed in maintenance mode, the host is removed from the cluster. Before the faulty host is removed, the customer workloads are migrated to a newly added host.

Azure VMware Solution monitors the following conditions on the host:

• Processor status
• Memory status
• Connection and power state
• Hardware fan status
• Network connectivity loss
• Hardware system board status
• Errors occurred on the disk(s) of a vSAN host
• Hardware voltage
• Hardware temperature status
• Hardware power status
• Storage status
• Connection failure

Backup and restore

Azure VMware Solution private cloud vCenter Server and HCX Manager (if enabled) configurations are on a daily backup schedule and NSX configuration has an hourly backup schedule. The backups are retained for a minimum of three days. Open a support request in the Azure portal to request restoration.

Azure VMware Solution continuously monitors the health of both the physical underlay and the VMware Solution components. When Azure VMware Solution detects a failure, it takes action to repair the failed components.

Next steps

Now that you've covered Azure VMware Solution private cloud concepts, you might want to learn about:

• Azure VMware Solution networking and interconnectivity concepts
• Azure VMware Solution storage concepts
• How to enable Azure VMware Solution resource