There are disks in both Google Compute Engine and Microsoft Windows Azure.
In Azure when you create and attach a Disk; behind the scenes it is a page-blob which gets created in the apecified Azure Storage Account. There isn't any exact same like AWS EBS in Azure. This disk can attached, reattached to instances.
https://developers.google.com/compute/docs/disks http://blogs.msdn.com/b/windowsazurestorage/archive/2012/06/28/exploring-windows-azure-drives-disks-and-images.aspx