Azure runs on a modified HyperV, right? Or are you saying they are using some other hypervisor there?
it does but i cannot tell why the azure performance is so different than on premises hyperv. i simply don’t know but the issues i’m describing here afaik did not affect azure instances. i do not know why but i thjnk it means there is a difference between on premises hyperv and azure hyperv or they do something to ensure the same issues don’t affect azure instances
but i simply don’t know why there is a difference
edit: if you search “hyperv rct bug” you will find forum posts fasts showing the timeline of this issue lasting years and many clients complaining that microsoft would not even acknowledge the issue publicly (or even in ms support cases) until very very recently
From my perspective, Microsoft doesn't want to deal with HyperV anymore, they want your machines up on Azure. I'd actively advise against HyperV simply because I don't see that Microsoft cares about on-premises.
† RCT == Changed Block Tracking for HyperV, basically faster backups by allowing the backup application to know exactly which blocks of the virtual disks have changed since the last backup and the backup application can do fast incrementals via this means.