My brother is using a hosting provider which is providing his company with a VM with Windows Server 2008 R2.
They unfortunately have to run the whole stack on one server, so my brother at least asked for separate drives for OS, IIS, DB, Logs, etc.
They provided him with 5 logical drives all on the same "physical" disk 0 (e.g. showing to the OS as a physical disk -- one VMDK).
Assuming that there's a reasonable churn across these various logical disks, would adding them as separate "physical" disks (VMDKs I suppose) make sense? It seems like there would still be a performance gain there but I'm unsure how best to go about proving it and haven't found any literature (yet) on the subject.
Yes, you don't have to prove it, it's common sense, it just costs money is all. Of course that 'single physical disk' could well be a VMDK on a datastore based on a LUN that's wide-striped across hundreds of disks - the only way to know is to ask EXACTLY what they're providing and EXACTLY how - then you'll be able to make an informed decision.