As the multi cloud adoption is increasing, many VxRail customers find themselves in situations, where they have deployments in multiple sites and started the consumption of vSphere based public cloud offerings.

As AWS, Azure and GCP provide vSphere offerings, application mobility is becoming problematic. Organizations need simplified application migration, workload rebalancing and business continuity across datacenters and clouds to operate their businesses.
While vMotion and backup technologies solved this problem within a single region, it is not a scalable solution in a multi cloud world.

Typical challenges for multi cloud migrations include incompatible software stacks, cross-site networking, security issues and business disruption

In this blog post, we take a closer look at VMware HCX to provide a hybrid interconnect to enable simple, secure and scalable application migration and mobility within and across data centers and clouds.

HCX connects vDS or NSX networks at the source site to a NSX logical networks at the destination site. This service can expedite the use of the destination environment’s resources by allowing virtual machines to be migrated into the networks without re-IP or complicated VM transformations, by leveraging the routing and security policies at the source site.

HCX Features

HCX is often referred to as “Swiss Army Knife” when it comes to migrations as it provides various migration technologies to fit different requirements:

  • HCX Bulk Migration uses the vSphere Replication protocol to transfer multiple virtual machines in parallel. Virtual machines are “rebooted” into the target. With the Bulk migration option, virtual machines can have their IP addresses updated as part of the migration operation.

  • HCX vMotion uses the VMware vMotion protocol to transfer individual virtual machines. Used with HCX Network Extension for zero-downtime migrations of applications that are sensitive to downtime.

  • HCX Cold Migration uses the VMware NFC protocol. This migration type is automatically selected when transferring powered-off virtual machines.

  • HCX vMotion with vSphere Replication combines Bulk and vMotion to deliver zero downtime failover for Virtual Machines prepared in parallel.

  • HCX OS-Assisted Migration is a migration technology which uses an agent in the Windows/Linux Virtual Machines to enable migrations to vSphere from non-vSphere


HCX Versions

HCX is available in two different version. HCX Advanced functionality is included in multiple SDDC bundles as well as through cloud partners. HCX Enterprise provides additional functionality and is available as an add-on license. 

HCX Advanced includes the ability to migrate using HCX vMotion as well as cold and bulk migrations. Networking features include, High Throughput L2 Network Extension, WAN optimization, Traffic Engineering, Automated VPN with Strong Encryption and secured Data Center Interconnectivity with built-in hybrid abstraction and hybrid interconnects. 

HCX Enterprise is an add-on license designed to deliver additional functionality. Building on HCX Advanced additional features including enhancements to HCX vMotion to allow for live bulk migration (Replication Assisted vMotion), migration of non-vSphere workloads to current vSphere versions (OS Assisted Migration), application discovery, migration planning and logical grouping (Mobility Groups), automated network management as VMs move (Mobility Optimized Networking).

HCX components

In the HCX site-to-site architecture, there a HCX source and an HCX destination environment. In both the source and the destination environments, HCX is deployed to the management zone, next to each site's vCenter Server, which provides a single management interface for VMware HCX. This HCX Manager provides a framework for deploying HCX service virtual machines across both the source and destination sites.

  • HCX-IX Interconnect Appliance: The HCX-IX service appliance provides replication and vMotion-based migration capabilities over the Internet and private lines to the destination site whereas providing strong encryption, traffic engineering, and virtual machine mobility.

The HCX-IX appliance includes deployment of the Mobility Agent service that appears as a host object in the vCenter server. Mobility Agent is the mechanism that HCX uses to perform vMotion, Cold, and Replication Assisted vMotion (RAV) migrations to a destination site.

  • HCX WAN Optimization Appliance: The VMware HCX WAN Optimization service improves performance characteristics of the private lines or Internet paths by applying WAN optimization techniques like the data de-duplication and line conditioning.

  • HCX Network Extension Virtual Appliance: The HCX Network Extension service provides layer 2 connectivity between sites. HCX Network Extension provides the ability to keep the same IP and MAC addresses during virtual machine migrations. When the Network Extension service is enabled on a Service Mesh, a pair of virtual appliances will be deployed: one in the source and one in the destination site.

  • HCX Sentinel Gateway Appliance: Using VMware HCX OS Assisted Migration (OSAM), you can migrate guest (non-vSphere) virtual machines from on-premises data centers to the cloud. The OSAM service has several components: the HCX Sentinel software that is installed on each virtual machine to be migrated, a Sentinel Gateway (SGW) appliance for connecting and forwarding guest workloads in the source environment, and a Sentinel Data Receiver (SDR) in the destination environment.

  • HCX Sentinel Data Receiver Appliance: The HCX Sentinel Data Receiver (SDR) appliance works with the HCX Sentinel Gateway appliance to receive, manage, and monitor data replication operations at the destination environment.

HCX migration to VMware Cloud on AWS
In the following example we are going to setup HCX for VMware Cloud on AWS and perform a live migration of a VM from on-premises to the public cloud.

  1. HCX is natively integrated into VMware Cloud on AWS. First, we need to activate HCX in the cloud console and allow inbound HCX traffic.

  1. Now we can deploy HCX on premises and link it to the existing vCenter Server.

  1. In the next steps we need to create Network Profiles for management and vMotion. When a service mesh is created, the network profile configurations are used to connect the deployed HCX appliances.

  1. We can now proceed to create Compute Profiles. A Compute Profile describes which HCX services run, and how they are deployed when the Service Mesh is created.

  1. We can now go ahead and create a site pairing between our on-premises implementation and VMware Cloud on AWS.

  1. After the sites are paired, we can create a service mesh to allow for vMotion between sites.

  1. Before we can perform a live migration of VMs we need to create a network extension of the required networks.

  1. After the network extension is established, we can initiate the migration using the HCX dashboard.