Create a VM from a Windows Image with 4 Empty Data Disks
{"type": "microsoft.compute/virtualmachines/extensions", "apiversion": "2020-06-01", "name": "[concat('vm-r1","-",copyindex(1),"/","installwebserver')]", "location": "[parameters('location-r1')]", "copy": {"name": "extensioncopy", "count": 3}, "dependson": ["vmcopy"], "properties": {"publisher": "microsoft.compute", "type": "customscriptextension", "typehandlerversion": "1.7", "autoupgrademinorversion": true, "settings": {"commandtoexecute": "powershell.exe install-windowsfeature -name web-server -includemanagementtools && powershell.exe remove-item "c:\\inetpub\\wwwroot\\iisstart.htm" && powershell.exe add-content -path "c:\\inetpub\\wwwroot\\iisstart.htm" -value $('hello world from " + $env:computername)"}}} 