Ultra slow download speeds from any service that uses Azure.

Isaac Cajiao Valle 5 Reputation points
2023-06-29T22:20:02.3566667+00:00

Hi. I'm been trying to figure out a performance issue i'm having with every service that uses Azure for their storage. My ISP provides me up to 1gbit simetrical bandwith but i'm not able to download anything from Azure faster that 300KB/s, my ISP ( Adamo Telecom Iberia(AS35699) ) has direct peering with Microsoft, so should have better performance on West Europe servers. I tried a speedtest (AzureSpeed.com) and same deal 300KB/s. A friend who has access to the Azure Storage panel changed a setting to use ISP peering instead of Microsoft network and it solved the issue for him, so the problem has to be in the Microsoft to ISP direct link. Dont know where i have to inform this issue so i let it here if someone can help.

Thanks.

Azure Files
Azure Files
An Azure service that offers file shares in the cloud.
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Azure Storage
Azure Storage
Globally unique resources that provide access to data management services and serve as the parent namespace for the services.
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  1. Sumarigo-MSFT 47,471 Reputation points Microsoft Employee Moderator
    2023-06-30T14:07:44.1166667+00:00

    @Isaac Cajiao Valle Welcome to Microsoft Q&A Forum, Thank you for posting your query here!

    There is no throttling on the Azure side, refer to below article. If the network and client machine can handle the traffic then we will send it.

    Here's a guide for troubleshooting high E2E latency:

    This article lists common problems related to Azure file share performance, and provides potential causes and workarounds: https://learn.microsoft.com/en-us/troubleshoot/azure/azure-storage/files-troubleshoot-performance?tabs=windows

    Azure File provide a best IO performance to all users accessing the server with high-importance to data integrity and fairness to all users in all scenarios.
    If you are facing any issue in downloading or uploading use azcopy tool.

    Is Azure File Share connected via Private Endpoint to your Azure environment like described in this graphic?

    https://learn.microsoft.com/en-us/azure/architecture/hybrid/azure-files-private#architecture

    Or if your Azure File Share is not using a private endpoint the access might be over your internet connection and not via Express Route.

    Performance tuning for file servers

    Can you download PerfInsights tool, for Performance data collection Windows
    Using PerfInsights:

    • Execute PerfInsights using the Azure Files scenario: PerfInsights.exe /r azurefiles /sr 9971**9
    • Select Y to agree to share diagnostic information
    • Select Y to agree PerfInsights EULA.
    • Reproduce the performance issue or make sure that it's occurring.
    • When enough data is collected , press any key to stop diagnostic data collection.
    • Retrieve the compressed file created under the current folder with format similar to "CollectedData_YYYY-MM-DD_HH-MM-FFF.zip"

    You might see slow performance when you try to transfer files to the Azure File service.

    If you don't have a specific minimum I/O size requirement, we recommend that you use 1 MiB as the I/O size for optimal performance.

    If you know the final size of a file that you are extending with writes, and your software doesn't have compatibility problems when the unwritten tail on the file contains zeros, then set the file size in advance instead of making every write an extending write.

    For testing purpose can you use Azcopy tools and check the speed and let me know the status. For transferring Files I would recommend to use AzCopy and File Storage for any transfer files(upload and download). In Azcopy throughput from a single instance will scale at least 20Gbps

    Additional information: Sometimes your proxies/VMs or whatever runs in the same datacenter, network requests does not leave the local network and the speed then depends on the infrastructure. (routers, firewalls, cables, etc). I'm sure they won't limit speed between their own infrastructure so services hosted on the same network works at full speed.

    Note: Windows OS/Windows Explorer is configured by default, it uses a 4K block size that will produce slower speeds for SMB compared to AzCopy/Storage Explorer which uses REST API.148042-image.png

    If the issue still persist, I would recommend you to contact support, so If you have a support plan, I request you file a support ticket, else please do let us know, we will try and help you get a one-time free technical support. In this case, could you send an email to AzCommunity[at]Microsoft[dot]com referencing this thread as well as your subscription ID. Please mention "ATTN subm" in the subject field. Thank you for your cooperation on this matter and look forward to your reply.

    Please let us know if you have any further queries. I’m happy to assist you further.


    Please do not forget to "Accept the answer” and “up-vote” wherever the information provided helps you, this can be beneficial to other community members.

    1 person found this answer helpful.

  2. JimmySalian-2011 42,511 Reputation points
    2023-06-30T09:49:33.85+00:00

    Hi,

    I will suggest you to raise a product feedback over here - https://feedback.azure.com/d365community/forum/8ae9bf04-8326-ec11-b6e6-000d3a4f0789

    also you can raise a support case with Microsoft to carry out a detailed investigation - https://azure.microsoft.com/en-ca/support/create-ticket/

    ==

    Please Accept the answer if the information helped you. This will help us and others in the community as well.

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  3. J.A 0 Reputation points
    2023-07-02T14:47:35.3166667+00:00

    I have the exact same issue with the same ISP Adamo AS35699 . The connection is via my ISP who have a direct peering with Microsoft in Espanix exchange. I can reproduce the issue with any file hosted in Azure (without CDN) and I also have a personal Azure subscription for testing purposes, however I do not have a support plan purchased. Another example is any content hosted in adoption.microsoft.com have the same slow speed such as https://adoption.microsoft.com/files/sharepoint/SharePoint-Adoption-Playbook.pptx Thanks

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