I'm installing OSISoft on a single windows 2008 VM in Azure and part of the instructions recommends having 4 drives for each application. However Azure will only allow 2 disks be attached to a VM. What alternatives do I have?
You need to use data disks and choose the different VM size - the VM size determines the amount of data disks that can be connected. https://azure.microsoft.com/en-us/documentation/articles/virtual-machines-windows-sizes/