Hi Nova team! tl;dr: we would like to contribute giving instances access to physical block devices directly on the compute hosts. Would this be accepted? Longer version: About 3 or 4 years ago, someone wrote a spec, so we'd be able to provide a local disk of a compute, directly to a VM to use. This was then rejected, because at the time, Cinder had the blockdevice drive, which was more or less achieving the same thing. Unfortunately, because nobody was maintaining the blockdevice driver in Cinder, and because there was no CI that could test it, the driver got removed. We've investigated how we could otherwise implement it, and one solution would be to use Cinder, but then we'd be going through an iSCSI export, which would drastically reduce performances. Another solution would be to manage KVM instances by hand, not touching anything to libvirt and/or OpenVSwitch, but then we would loose the ease of using the Nova API, so we would prefer to avoid this direction. So we (ie: employees in my company) need to ask the Nova team: would you consider a spec to do what was rejected before, since there's now no other good enough alternative? Our current goal is to be able to provide a disk directly to a VM, so that we could build Ceph clusters with an hyper-converged model (ie: storage hosted on the compute nodes). In this model, we wouldn't need live-migration of a VM with an attached physical block device (though the feature could be added on a later stage). Before we start investigating how this can be done, I need to know if this has at least some chances to be accepted or not. If there is, then we'll probably start an experimental patch locally, then write a spec to properly start this project. So please let us know. Cheers, Thomas Goirand (zigo)