you can attach exising this, using a csv list with the disk name and lun, like:
diskname,lun
disk1,0
disk2,1
disk3,2

and use a script like:
$rg = “ResourceGroupName”
$vmname = “VirtualMachineName”
$vm = Get-AzVM -ResourceGroupName $rg -Name $vmname
$disklist = Import-Csv ./diskname.csv
foreach ($disk in $disklist) {
$datadisk = Get-AzDisk -ResourceGroupName $rg -DiskName $disk.diskname
$vm = Add-AzVMDataDisk -VM $vm -CreateOption Attach -ManagedDiskId $datadisk.Id -Lun $disk.lun
}
Update-AzVM -VM $vm -ResourceGroupName $rg

of course I have not tested this 🙂

Do you have, by any chance, a script for a scenario in which the disks already exist?

I need to create a routine to attach existing managed data disks to a VM, but I couldn’t quite figure it out how to do it yet.

Thanks in advance!