@Alex King Welcome to Microsoft Q&A Forum, thank you for posting your query here!
To limit the file size during an upload to Azure Blob Storage using a Shared Access Signature (SAS), you can’t directly specify the file size limit in the SAS itself. However, you can enforce the limit by implementing a check in your application logic before generating the SAS.
For instance, you could use Azure Functions or another server-side logic to check the file size before providing the SAS to the user for upload. If the file exceeds the specified size limit, the SAS would not be generated, and the upload would not proceed.
Additionally, you can look into Azure Blob Storage’s event-driven architecture with Azure Event Grid, which can react to blob creation events. You could create a subscription to these events and trigger a function to check the file size after the upload. If the file size exceeds the limit, you can then take appropriate actions, such as deleting the file.
Remember to also consider the maximum file size limits that Azure Blob Storage supports for different blob types when designing your solution.
Additional information: https://learn.microsoft.com/en-us/answers/questions/891323/how-to-increase-file-upload-capacity-over-100mb
And Azure Blob Storage Limits: https://learn.microsoft.com/en-us/azure/azure-resource-manager/management/azure-subscription-service-limits#azure-blob-storage-limits
Please let us know if you have any further queries. I’m happy to assist you further.
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