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AWS details customer's 2,000-instance Windows Server 2016 to 2025 upgrade

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This post details how a financial services customer upgraded over 2,000 Amazon EC2 instances from Windows Server 2016 to Windows Server 2025. The customer chose an in-place upgrade approach to minimize downtime and preserve network configurations, a critical factor for their environment. AWS provided a Systems Manager automation document to facilitate this large-scale upgrade, outlining prerequisites like licensing model conversion and EC2Launch v2 updates.

  • →Customer faces large-scale Windows Server upgrade challenge
  • →Three upgrade approaches evaluated for EC2 instances
  • →In-place upgrade chosen for network identity and automation
  • →Key prerequisites for Windows Server in-place upgrades
  • →AWS Systems Manager automates large-scale upgrades
Notes (5) ›
  • Customer faces large-scale Windows Server upgrade challenge

    A financial services customer needed to upgrade over 2,000 Amazon EC2 instances running Windows Server 2016 to Windows Server 2025 before the former's end of support in January 2027, with strict requirements for minimal downtime and preserved configurations.

  • Three upgrade approaches evaluated for EC2 instances

    AWS presented three options: a fresh instance with application migration, cloning instances for upgrade, and an in-place upgrade. Each had distinct advantages and considerations regarding downtime, data synchronization, configuration preservation, and cost.

  • In-place upgrade chosen for network identity and automation

    The customer selected the in-place upgrade due to its ability to preserve IP addresses and hostnames, avoid data synchronization complexity at scale, and its suitability for automation, accepting the 1-2 hour downtime window per instance.

  • Key prerequisites for Windows Server in-place upgrades

    Essential steps before upgrading include verifying and converting the licensing model to 'License Included' (LI) for Windows Server 2025, updating EC2Launch from v1 to v2, optionally updating ENA and EBS drivers, and creating EBS snapshot backups for rollback.

  • AWS Systems Manager automates large-scale upgrades

    AWS provided a custom SSM automation document, EC2-InPlaceUpgradeToWindows2025, to automate the in-place upgrade process, including validation of OS, disk space, EBS backing, and Nitro instance compatibility.

Read the original announcement →

https://aws.amazon.com/blogs/modernizing-with-aws/how-a-customer-upgraded-over-2000-windows-server-2016-to-2025-on-amazon-ec2/

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