How many disks do all Azure virtual machines have at least?

The minimum number of disks that all Azure virtual machines have is one disk. Every Azure virtual machine automatically comes with a temporary disk and at least one OS disk. The OS disk is essential as it contains the operating system for the virtual machine to run.

If a virtual machine has other disks attached, such as data disks, these are additional to the required OS disk. However, the key point here is that regardless of the size or configuration of the virtual machine, the fundamental requirement includes at least one OS disk, making the correct answer one.