I have an Ubuntu VM with a separate mounted data disk on a Premium storage account. The data disk is very large and as a result it is costing me more than I would like. I've tried copying the VHD according to the instructions here, but the operation completes immediately and the resulting VHD size is 0 or -1 according to Powershell (Azure portal shows the proper size, however). Regardless, I detached the premium disk and attached the standard disk in its place. This went poorly, resulting in an initial error message that the disk size of -512 bytes was invalid, and subsequent error messages of
Failed to attach/detach existing disk 'datadrive' to the virtual machine 'myservername'. Error: There is already a lease on the storage container holding the blob with URI
where "attach/detach" was dependent on which operation I was performing. I tried deleting the new standard storage account and starting the process over from scratch, but still had no luck. Ultimately I re-attached the existing disk on the premium account and I was able to start the machine successfully once more, but trying to migrate to the standard storage account was a miserable failure.
Is migrating a data disk from a premium storage account down to standard possible? And if so, what are the steps?