c8322bc7_imits__Quotas__and_Constraints__Comments
[Limit identifier] Maximum number of volumes that can be processed in parallel for backup, restore, or clone [Limit] 16 [Comments] 
If there are more than 16 volumes, they will be processed sequentially as processing slots become available. New backups of a cloned or a restored volume cannot occur until the operation is finished.
Microsoft Azure Subscription and Service Limits, Quotas, and Constraints
Comments