We're planning to migrate our on-premises environment to Azure. The current estate includes 10 file servers, 15 SQL servers, and around 70 application servers. We already have a production subscription and intend to place production workloads there, while the SQL and application servers will initially support development and system integration testing. Should we create a separate development/test subscription, and are there licensing or SLA considerations we should understand? Our initial approach is lift-and-shift, but we'd also like guidance on where modernization or Azure platform services might make sense. We also have about 50 TB of archive files that only need to be accessed occasionally. What Azure storage option would provide a practical balance between cost and occasional access?
4 Answers
Lift-and-shift can reduce the initial migration effort, but moving dozens of virtual machines without redesigning them is often more expensive over time. Use Azure Migrate to assess dependencies, right-size the machines, and identify candidates for App Service, managed databases, or containers. The Cloud Adoption Framework and Azure landing zone guidance are good places to start. For the 50 TB archive, Blob Storage with lifecycle policies is a strong fit: keep frequently accessed data in a hotter tier, move older data to cool or archive storage, and account for retrieval charges and access delays before committing to the archive tier.
A separate dev/test subscription is usually worth considering, especially when the workloads qualify for Visual Studio or other dev/test licensing benefits. Be careful, though: dev/test offers and terms depend on your agreement type, and some dev/test environments may have different SLA or access restrictions than production. Also assess your network connection to Azure and how much downtime you can tolerate before choosing a migration method. For the archive, Blob Storage is generally much cheaper than Azure Files. If the data changes rarely, you can transfer it with AzCopy and use a cooler or archive tier, depending on how quickly you need to retrieve it.
This is a significant migration rather than a quick server move. Build the subscription and landing-zone structure first, including identity, networking, security, governance, backup, monitoring, and cost controls. A qualified Microsoft partner can help with the assessment and may be eligible for migration funding or incentives. Validate the exact program terms against your licensing agreement before relying on any savings.
If the existing hardware is nearing replacement, a lift-and-shift approach can still be reasonable as a first stage, particularly if virtualization or licensing costs are increasing. Just treat it as phase one rather than the final architecture: monitor usage, right-size CPU and memory, review SQL configurations, and gradually move suitable workloads to PaaS or container-based services. For archive data, Azure Blob Storage is typically the lowest-cost option. Azure Files may be preferable if users need a familiar SMB or DFS-style share, but it will generally cost more than blob storage.
The application servers may be a mix of web and application tiers, so they’re good candidates for modernization after the first migration wave. An Azure Migrate and Modernize engagement with an experienced Microsoft partner may also provide assessment help and potentially offset some project costs through available incentives.