Hi all, tl;dr: We really need ops feedback about any direct need to retain this feature. Since the early days, Nova has supported the notion of "direct linux kernel boot" (with libvirt/kvm at least). This means each bootable image in Glance is actually three parts: a disk image, a ramdisk image, and a kernel. Booting the instance involves putting the kernel and ramdisk into memory in a special way that the kernel can immediately start booting instead of doing things like running the bootloader like a normal system does. This is present in Nova because of long-ago Amazon compatibility, as this is how Xen paravirt guests used to work for them. I think that in the early days of Nova, compatibility with the _actual_ images used on Amazon was important, but I think that is no longer something we need to care about today, just as we have deprecated EC2 API compatibility. It should also be noted that some of it is broken, and the recent CVE fixes have broken it like three times in the last 30 days. Continuing to support it makes the code more complex and fragile, and arguably less secure. So, I'm asking for operator feedback on this question: Do you need this feature, and if so, why? Speak now or expect to see it deprecated for removal very soon. Thanks! --Dan