We are currently experiencing an issue where the IO performance of our SQL Server running on an Azure VM isn't quite up to snuff.
We are running a Azure VM (Standard DS2). This one has a 127 GB SSD C: drive throttled at 64 MB/s. We added an extra drive to this VM because we believe it should be able to perform faster than the limited 64 MB/s.
When doing copy operations (using AZCopy) to the newly added & faster F: drive we can see that the IO speeds are a lot higher. However, when restoring a database backup from this new & fast F: drive to a location on that same drive we're still getting throttled at 64MB/s.
We've contacted Microsoft about this but up until now they were unable to provide a proper explanation. Anyone has any experience with this?
Attached you'll find a screenshot of the performance monitor during the restore, showing that the read & write operations are only happening on the new F: drive, while showing a fairly stable 64MB/s.