What’s New in HCX 4.1 Part III – Predictive Migration Estimations & Other Highlights

This is the 3rd and final installment of What’s New in HCX 4.1. You can find I & II below:

What’s New in HCX 4.1 Part II – Seed Checkpoint for Bulk Migration

What’s New in HCX 4.1 Part I – General Availability for Mobility Optimized Networking

Predictive Estimates for HCX Bulk Migration

There is an initiative within the HCX team to provide tools that take reduce the guesswork when planning application migrations.

For the initial phase of this initiative two distinct capabilities were added: Real-time Estimates for Bulk Migration (4.0) and Predictive Estimates for Bulk Migration (4.1)

Real-time Migration Estimates for Bulk Migration (from HCX 4.0) provides a “time to completion” for migrations in progress, during the transfer phase (the full synchronization of the virtual machine disks, before we transition to copying VM changes). The time is provided on the right side of the progress column, in the migration interface. Here’s what that looks like:

Predictive Estimates for Bulk Migration (from HCX 4.1) provides migration estimates for virtual machine mobility groups before they are migrated. This functionality is available for Mobility Groups in a draft state.

The predictor modeling is based on data collected from real migrations. Multiple data points (like the rate of checksum operations, datastore types, transfer rates, and parallel operations) are evaluated when HCX is building out the prediction model. Some things to know:

  • The initial predictive model is built by performing 50 migrations (direction matters)
  • The model is updated with every 25 new migrations. And up to 300 migrations are contained in the model (older migrations roll out)
  • HCX 4.1 is required across the site paired managers to use this feature.

For HCX 4.0 Users

Deployments already running HCX 4.0 that have not already upgraded will (for the first time) be able to use the In-Service Upgrade Mode when upgrading the HCX Network Extension appliances to HCX4.1. As a refresher – this new upgrade mode will use available IP pools to deploy a new appliance, fully configure the HCX Transport tunnels and lastly transition the bridging function (largely avoiding forwarding downtime). More about in-service mode here.

HCX 4.0 added migration data collection, Bulk Migrations with HCX 4.0 will be used towards the 4.1 requirements for the Predictive Estimates feature.


Updates for “Mobility Agent” Migrations (HCX vMotion & Replication Assisted vMotion

Virtual Machines with 24TB memory (previous limit 1TB)

Virtual Machines with 768 vCPU (previous limit 128 vCPU)

RAV Migrations to clouds with VSAN Datastores up to 30TB (previous limit 2TB)


Reminder about Evacuation of Legacy vSphere Environments (Last Call for vSphere 6.0 Projects)

Technically there is no direct correlation to HCX 4.1. Really I just want to highlight what is coming down.

How do we define Legacy vSphere ?

End of Support vSphere installations that have not reached End of Technical Guidance

What does that mean today?

vSphere 6.0 reached End of Support March 12, 2020 (Entering the Technical Guidance Phase)

This means two things in HCX terms:

1. As of March 12, 2020 – vSphere 6.0 cannot be used for an HCX Cloud deployments. vSphere 6.5 or later should be used.

2. Any version of HCX can be used to evacuate the environment. End of Support should be the signal for evacuation project to be prioritized!

vSphere 6.0 reaches the End of Technical Guidance on March 12, 2022

Upon reaching End of Technical Guidance

(vSphere 6.5 reaches End of Support November 15, 2021)

Good time for early migration planning.


AND that covers it! Happy Independence Day Week(end)!


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