VM M64s size and problems starting after deallocating to add UltaDisk

Question

Hello have VM with size M64s and have added 2 Premium SSD drive along with 2 Standard HDD
Enabled the UltraDisk option and was able to add/attach the UltraDisk via the Microsoft DevOPS portal.( because do not have rights to create in Portal.

The message that appears in the DevOps logs in not very helpful.

Long running operation failed with status 'Failed'. Additional Info:'Allocation failed. VM(s) with the following constraints cannot be allocated, because the condition is too restrictive. Please remove some constraints and try again. Constraints applied are:

• UltraSSD Disks
• VM Size

The UltraSSD disk was configured with 3000 IOPS

Thanks

Answer 1

Hi @BarryShay-3750

Thanks for reaching out to Microsoft Q&A Platform ,

“Allocation failures. Allocation failures were specifically observed when a VM was configured for "Enable Ultra Disk compatibility".

Generally, allocation failure is rare and transient in nature and resolve on its own as soon as enough capacity is available.
Under certain circumstances manual intervention might be required, like in case of multiple constraints based on VM configuration.

Since your VM was had a mix of Standard and UltraSSD disks, the underlying hardware supporting all these constraints were limited.
This resulted in allocation failure during VM start since Azure platform was unable to locate hardware with enough capacity that can support all the above-mentioned constraints

I would suggest you to retry the operation and if you are still experiencing the same issue , Please do open an Support ticket and the failure can be investigated in detail .

Please do let me know if you have any additional questions on the same or request you to accept the answer if this served your request .

Thanks & Regards,
Pradeep