what is the max concurrent request limit for disk creation

Question

so lets say if i have 1000 instance under one azure subscription and i want to attach new data disk to all of my 1000 instance, can i send 1000 concurrent request for new data disk creation in parallel.

if disk creation is possible next step would be attach those newly created disk to the respective instance. do we have limit for that also ?

if no , what is the limit for that same.

Answer 1

Hi @Ankur Jain

To address your query regarding attaching new data disks to 1000 instances under one Azure subscription.
You can create a maximum of 49 managed disks concurrently from an existing managed disk. Therefore, if you have 1,000 instances and want to attach new data disks to all of them, you cannot send 1,000 concurrent requests for new data disk creation in parallel. You would need to create the disks in batches of up to 49 at a time.
Azure Resource Manager may throttle requests if too many are sent simultaneously. It's best to batch requests.
https://learn.microsoft.com/en-us/azure/virtual-machines/disks-scalability-targets

As for attaching the newly created disks to the respective instances, there is no specific limit mentioned in the context regarding the number of disks that can be attached to virtual machines. However, the number of data disks that can be attached to an Azure virtual machine depends on the VM size and type. For example, a Standard_DS15_v2 VM can have up to 64 data disks attached. There isn't a specific limit on the number of concurrent requests for attaching disks, but it's always good to monitor for any throttling or performance issues.

Please follow the below Microsoft documentations for more details.
Azure subscription and service limits, quotas, and constraints

Hope the above answer helps! Please let us know do you have any further queries.

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Answer 2

Hello Ankur Jain,

Welcome to the Microsoft Q&A and thank you for posting your questions here.

I understand that you would like to know the max concurrent request limit for disk creation.

Regarding your questions:

1. The maximum number of concurrent requests for creating disks in Azure is 49 disks at a time. Therefore, you cannot send 1000 concurrent requests; you would need to batch your requests into groups of 49. https://learn.microsoft.com/en-us/azure/virtual-machines/disks-scalability-targets
2. About attaching Disks to Instances. The number of disks you can attach to a VM depends on the VM SKU. For example, a Standard_DS15_v2 VM can support up to 64 data disks. While there is no explicit limit on the number of disks you can attach concurrently, you should consider the overall performance and potential throttling. Attaching a large number of disks simultaneously can lead to performance degradation and throttling issues.

Best practices recommendations

• For creating 1000 disks, batch your requests into groups of 49 to stay within the concurrent request limit.
• When attaching disks, monitor the performance and be aware of potential throttling. Attach disks in smaller batches if necessary to avoid performance issues.

I hope this is helpful! Do not hesitate to let me know if you have any other questions.

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