I have been following the patches on nvme support on the list and was wondering: If I wanted to build a vm host to be on the bleeding edge for nvme and spdk fun in libvirt, which linux distro -- fedora/ubuntu/centos/etc -- should I pick?

I have been following the patches on nvme support on the list and was wondering: If I wanted to build a vm host to be on the bleeding edge for nvme and spdk fun in libvirt, which linux distro -- fedora/ubuntu/centos/etc -- should I pick?

On Thu, Dec 12, 2019 at 5:40 AM Michal Privoznik <mprivozn(a)redhat.com&gt; wrote: > > On 11/27/19 4:12 PM, Mauricio Tavares wrote: >> I have been following the patches on nvme support on the list and was >> wondering: If I wanted to build a vm host to be on the bleeding edge >> for nvme and spdk fun in libvirt, which linux distro -- >> fedora/ubuntu/centos/etc -- should I pick? >> > > For NVMe itself it probably doesn't matter as it doesn't require any > special library. However, I'm not so sure about SPDK, esp. whether my > NVMe patches is what you really need? My patches enable the only missing > combination: > > host kernel storage stack + qemu storage stack = <disk type='block> > <source dev='/dev/nvme0n1'/> </disk> > This has disadvantage of latency added by both stacks, but allows > migration. > > neither host kernel nor qemu storage stack = <hostdev/> (aka PCI assignment) > This offers near bare metal latencies, but prohibits migration. > > qemu storage stack only = <disk type='nvme'/> > This is what my patches implement and should combine the above two: > small latencies and ability to migrate. > That is actually my question: is handing the hard drive through PCI assignment faster or slowe than disk type='nvme'?