Migrate your Azure Functions applications

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Migrate your Azure Functions applications

Martin Konicek (DHL IT Services) 20

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Migrate your Azure Functions applications from the Linux Consumption plan to the Flex Consumption plan before 30 September 2028

I have a few apps on Pricing Tier: Dynamic (Y1:0) and Operating System: Linux

What I do not know how can I migrate this plan, I have not found any button for it neither documentation. Can you please advice.

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Answer 1

Hello Martin Konicek (DHL IT Services),

Thanks for your question about migrating Azure Functions from Linux Consumption (Dynamic Y1) to Flex Consumption. There's no direct "migration button" because the plans have significant architectural differences you'll need to create a new Flex Consumption app and migrate your configuration. Here's the correct approach:

Migration Steps

Check Eligibility: Ensure you have Azure CLI 2.77.0 or later installed. Run this command to list eligible apps for migration:

text
az functionapp flex-migration list

This returns eligible and ineligible apps with reasons (e.g., unsupported region or language stack).

Start Migration: Use the new Azure CLI migration command to automate most steps:

text
az functionapp flex-migration start --source-name <SOURCE_APP_NAME> --source-resource-group <SOURCE_RG> --name <NEW_APP_NAME> --resource-group <NEW_RG>

Create the new resource group in the same region as your current app first.

Manual Migration (Alternative): If you prefer full control or the CLI doesn't work, follow the official migration guide, which covers creating a new Flex app, transferring settings (excluding deprecated ones), configuring networking, managed identities, and deploying code.

Key Points

No in-place upgrade: You create a new Flex Consumption app, not convert the existing one.

Deadline: Migrate before September 30, 2028 to avoid service disruptions.

Benefits: Flex offers better performance, VNET integration, always-ready instances, and improved scaling.

The Azure CLI migration command (available since August 2025) simplifies the process significantly compared to manual steps. Check the migration guide for detailed instructions!

Best Regards,

Jerald Felix

Mohsin Khan 85 Reputation points

2026-10-24T21:03:33.85+00:00

Hello @Jerald Felix

When I run the following command in Azure Cloud Shell, it does not return any resources:

az functionapp flex-migration list

Can I conclude that there are no Function Apps eligible for migration based on this result, or could there be other reasons why the command is not returning any resources?

Additionally, when I query Azure Resource Graph using the KQL below, I can see a few Function Apps that appear to match the criteria.

resources | where type == 'microsoft.web/sites' | where ['kind'] == 'functionapp,linux' | where properties.sku == 'Dynamic' | extend siteProperties = todynamic(properties.siteProperties.properties) | mv-expand siteProperties | where siteProperties.name == 'LinuxFxVersion' | project name, location, resourceGroup, stack = tostring(siteProperties.value)

Could you please clarify which of these methods should be considered the source of truth for the migration notification? If the CLI command returns no resources while the KQL query identifies Function Apps, how should we validate whether those applications are actually eligible for migration?

Thanks.