Check out this excellent new article by Claudio Popescu and Mihai Criveti. Not only does it offer some practical help for recovering stuck instances but it demonstrates some powerful tools and techniques.
Summary: Suppose something went wrong and you discover you have an inaccessible Linux® instance on IBM® SmartCloud Enterprise? What can you do? The authors of this article walk you through the steps to recover an inaccessible Linux instance. They show how to capture a private image, copy it to persistent storage, use QEMU to boot the captured image or mount it using kpartx, fix the problem, and then import the image back into the cloud.