Your VMware migration methods matter, and each approach changes how workloads move, when disruption happens, and how much operational risk IT teams need to manage.
If you’re asking what kind of migration approach should I use for my environment, warm import is one of those methods. In environments using StorMagic SvHCI our hyperconverged infrastructure (HCI) software, warm import is a VMware exit migration method that keeps workloads running while migration happens in the background, then finishes with a short, controlled cutover.
It’s simple in concept, but it changes how migration feels in practice.
VMware Exit Migration Approaches: A Simple Comparison
| Approach | What It Is | Downtime Model | Best Fit Scenario |
| Warm Import (StorMagic approach) | Workloads stay running in VMware while data is synchronized into StorMagic SvHCI, then a controlled cutover completes migration | Low. Short final cutover window | Distributed environments, edge locations, phased VMware migration |
| Lift-and-Shift Migration | Virtual machines are exported or copied into a new environment, often with a shutdown during transfer | Medium to high depending on method | Smaller environments with planned maintenance windows |
| Big-Bang Migration | Entire VMware environment is migrated in a single coordinated event, usually over a weekend | High during cutover | Simple or non-critical environments where downtime is acceptable |
| Phased Migration | Workloads are migrated in groups over time as part of a structured plan | Medium, depends on batching and scheduling | Large enterprises with multiple sites or complex environments |
What is Warm Import?
Warm import keeps things straightforward. Your virtual machines (VMs) stay running in VMware while data is copied and synchronized into your HCI software in the background. Nothing is shut down at the start. Once everything is in sync and validated, you complete a short cutover window and move the workload into the new environment.
Here’s what that looks like:
- The VM keeps running in VMware
- Data sync happens in the background
- The system is validated before cutover
- A short maintenance window completes the move
- The workload runs in SvHCI
That’s it, most of the migration happens while the system is still live, and with this approach, VMware migration downtime is low with a short, final cutover window.
How Warm Import Solves VMware Replacement Problems
With a lot of VMware replacement options, the headache comes from having to swap your hardware out and transition to new hardware. With one or two environments, that’s okay, with a data center, that’s okay, and when you’re in close proximity to that location, that’s okay.
But when you’ve got 100 remote locations, and for each one of those sites you’re having to send people out there, it becomes a headache.
You’re effectively talking about one truck roll to get the new systems in and transition across to the new environment, and then another truck roll to take the old systems out. You can imagine the kind of costs that introduces, let alone hardware supply issues, increasing hardware costs, and all the other headaches that come with these projects.
StorMagic enables you to attain software flexibility, and layer straight on top of existing deployed infrastructure, easing your transition away from VMware. Not only that, but being able to do it all remotely as well.
A Real-Life Example of the Warm Import Method
A large multi-site fuel retailer needed to migrate VMware-based infrastructure at remote gas station locations to our hyperconverged infrastructure, the SVHCI environment, without replacing hardware or sending engineers on-site.
The organization operated VMware virtual machines (VMs) across distributed edge locations using compact cluster deployments. To reduce cost and complexity, the migration was performed remotely using VPN access, management jump boxes, and out-of-band management tools such as iDRAC.
Workloads were first moved onto a single node while the second node was rebuilt with SVHCI. Because the SVHCI installation image is only around 300 MB, it could be deployed efficiently across limited WAN connections, avoiding the challenges associated with transferring multi-gigabyte operating system images.
Once installed, administrators recreated the existing VMware virtual networking configuration within SVHCI, including VLANs and port groups, using a familiar workflow.
The organization then used the built-in SVHCI import utilities to migrate VMs directly from VMware. Using warm import functionality, VM data was synchronized while workloads remained live in production, allowing administrators to choose a short cutover window to power down the VM in VMware and restart it in SVHCI with minimal downtime.
This approach enabled the organization to transition away from VMware with minimal disruption, no hardware refresh requirements, and no on-site intervention.
The examples referenced here are based on StorMagic SVHCI functionality, including the lightweight SVHCI deployment image, VMware import utilities, and warm migration capabilities used to synchronize live VM data prior to cutover. You can learn about SvHCI and its great features here.
How Warm Import Works in Practice
If you were to use StorMagic SvSAN or SVHCI, the warm import functionality would allow VMware VMs to be migrated with minimal downtime and no requirement for new hardware.
Existing workloads would first be consolidated onto a single VMware node while the second node is rebuilt with SVHCI, for example.
Once installed, we’d recreate the required virtual networking configuration, including VLANs and port groups, using workflows similar to VMware. The built-in VM import utilities would then connect to the VMware environment, either through vCenter or directly to a host.
A trigger script would start the migration process, allowing VM data to be transferred across either the management network or a dedicated back-end connection.
Using warm import functionality, VM data would be continuously synchronized while the workload remains live in production, enabling administrators to choose a controlled cutover window to shut down the VM in VMware and power it back on within the StorMagic environment with minimal service interruption.
Simplify Edge Infrastructure Migrations with StorMagic
For organizations looking to transition away from VMware, particularly across distributed edge and remote environments, minimizing disruption is critical. StorMagic SvSAN and SVHCI provide a flexible approach that allows existing infrastructure to be reused while reducing the operational complexity typically associated with large-scale migration projects. If this sounds like something you’re interested in, our you’d like to learn more about StorMagic SvHCI, you can watch an on-demand demo of our software here.
