Choosing the Right Virtual Machine Migration Path: The Wheres

Virtual Machine Migration - The Wheres

Sep 19, 2024 by Brent Earls

Great. You’ve picked your vendor of choice, you’ve figured out the ecosystem you need to surround it for the functionality you want, and you’ve identified how you’re going to move to it. During all of that, did you think of WHERE you’re going to move the new hypervisor?

Physical Server and Storage Considerations

Over the past couple of decades, VMware has led many companies to reduce physical server counts—a good thing overall. But now, as you migrate to a new hypervisor… where are you going to put it? You’ll need a fresh, supported physical server for your production environment, not some old hardware lying around.

Some companies opt to rebuild their +1 server from their existing n+1 cluster. This works, but until everything is fully migrated, both old and new sides won’t be redundant. Is that acceptable? Do you need to buy some new servers for the new hypervisor? Maybe you’re already ready for a refresh, which would be the optimal situation as you could have a full N+1 solution on both VMware as well as your new hypervisor.

Even if you are ready to buy new servers, what are you going to do about storage?

During migration, you’ll manage dual copies of servers. Your old datastores likely house 10-20+ VMs each, and moving to the new platform means holding onto the old datastore and SAN LUN until everything is transferred. This means you’ll need ample storage to serve up a new LUN to the new cluster, migrate everything, validate that it all works correctly, and then delete the old LUN. Modern deduplication SHOULD help, but differences in block sizes and formatting might affect efficiency, not to mention backup considerations.

Backup and Disaster Recovery Challenges

When migrating production workloads, continuous backups are crucial. If you’re switching backup solutions to support the new hypervisor, you’ll need space for new backups and compliance with retention policies. Depending on the way you’re currently doing backups, if they are integrated into VMware, you’ll probably have to start a new backup chain on your new hypervisor. Worse, if you’re moving from one backup solution to another to be able to support the new hypervisor, you have to have somewhere to install it AND somewhere to store the backups. Also, don’t forget your long term retention needs. 

It’s often not that hard to have enough space to start a new backup chain when a few servers move over, and then to clean up old backups – but can you actually clean the old ones up? Do you have to keep backups for certain time periods for legal reasons or DR requirements? This can double your backup space needs, and unless your server was grossly oversized from the start, you probably don’t have that much space sitting around.

Finally, don’t forget your DR site. Many VMware environments have a dedicated DR site with hosts and storage – but what will it take to migrate that DR site to your new vendor? Can you temporarily forego DR during the transition, or will you need additional servers and storage to run both environments simultaneously?

Addressing Logistical Challenges

All of these logistical questions are the simple things that tend to slip through the cracks when thinking through a major migration such as this, largely because, for the last 15 or so years, all migrations have been from VMware to VMware, which is about as easy a migration as possible.

Addressing the logistical challenges of where to deploy your new hypervisor is crucial for a smooth migration. From ensuring you have the right physical servers and storage to managing continuous backups and maintaining your DR site, these considerations can make or break your transition.

Next Steps: Timing Your Migration

In the next blog of our series, we’ll dive into the timing of your migration. Stay tuned as we explore when the right time is to make the move and how to plan your migration timeline effectively to minimize disruption and maximize efficiency.

If you’d like more information about the evolving changes coming from VMware and how it may impact your IT infrastructure, please contact us by calling (502) 240-0404 or emailing info@mirazon.com

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