The ext4 file system is now being developed using a regression test system which uses a Google Compute Engine (GCE) Virtual Machine (VM) to run xfstests in a test appliance. This talk will: * Explore the advantages of using Cloud-based VM’s for kernel testing and development, and how this has improved the development process in the ext4 development community. * Describe how to create bootable GCE images which are used as the test appliance in an automated and reproducible procedure, by scripting the GCE commands necessary to start with a Debian image, and customize it by installing the regression test suite. * Demonstrate the techniques used to run a test kernel in a Cloud VM by using a front-end script which uploads the test kernel from the developer’s build tree, and then uses kexec to transition from the standard Debian kernel to the kernel to be tested.