This thread contains known issues in EC2 migrations.
- Citrix virtual machines are not supported. "Citrix Tools for Virtual Machines" should be uninstalled in order to clone Citrix server. See AWS documentation.
- Every volume you clone should have approximately 300 Mb of free space for successful imaging.
- Data volumes are not attached to the instance automatically. Use AWS management console to attach them.
- Windows 2008R2 Server Web Edition is not supported
- Your Windows installation should be located on drive C:. Amazon EC2 fails to accept images of Windows installed on drive other than C:.