Azure using SRE, I call BS. You don’t see underlying storage, it’s mounted as either SCSI or NVMe device as one HD. It’s obviously backed by massive fleet of drives just like EBS.
I was wrong about it being a spinning disk, ROTA=1 is just how Linux reports Azure virtual disks. But the underlying frustration stands: my home NVMe does the same copy in a fraction of the time because it can do 500K+ IOPS with no virtualization overhead. Azure caps this "Premium SSD" at 7,500 IOPS, so a small-file-heavy copy crawls at 85 MB/s despite 250 MB/s provisioned throughput. You're paying SSD prices for artificially throttled performance — the hardware may be SSD, but the performance is just awful. Paying $900/month for the highest level Premium SSD, attached to a large instance, and it's significantly slower than a $200 SSD from 5 years ago.
Sure the downside of virtualization is all disk calls are over the network which is way slower then local NVMe call. Upside is hardware failures are quickly handled.
