Virtual machine-level disk bursting is a new feature that allows your virtual machine to burst its disk IO and MiB/s throughput performance for a short time daily to handle unforeseen spikey disk traffic smoothly and process batched jobs with speed. The feature is now enabled on all Azure Lsv2-series virtual machines.
More virtual machine types support will come in the following months.
More details about this feature are available here https://docs.microsoft.com/en-us/azure/virtual-machines/linux/disk-bursting