Thanks for responding. Others have told me the same--that libvirt is doing its thing in user space. The process of OpenNebula actually clones a copy of the image so this image was freshly created and there's no way it could have been mapped elsewhere. In other news--by just taking the simple step of putting another different virtual machine image into ceph and trying again, things actually appear to have worked. more later. Steve Timm On Wed, 24 Sep 2014, Robert LeBlanc wrote: > Could this be a lock issue? From what I understand, librbd does not create an rbd device, it is all done in > userspace. I would make sure that you have unmapped the image from all machines and try it again. I haven't > done a lot with librbd myself, but my co-workers have it working just fine with KVM. > > On Wed, Sep 24, 2014 at 8:29 AM, Steven Timm <timm at fnal.gov> wrote: > > I have been trying for quite some time to launch a KVM VM > from a CEPH RBD volume using OpenNebula.? I have gotten past the permissions issues and to the > point where kvm can actually > start a virtual machine, but we are getting a "Geom Error" > as soon as the virt console comes up. > (note, not a GRUB Geom error). > As far as I can tell this means that the kvm bios > can't understand enough of the geometry of the disk file as presented by RBD (which is a RAW > format image) to even find the boot sector > to get as far as GRUB.? Have not seen anything with this specific > error in Google though. > > The hardware that I am using for the Ceph test is going away > at the end of this week and if I can't get past this problem in > the next couple days I will have to recommend to my management > that Ceph is not ready for my production cloud environment.? Appreciate the help we have gotten > thus far and hope the list can come through > one more time. > > To rehash--I have posted this on other threads before: > Sci. Linux 6.5 (redhat clone) + Kernel 3.10 + ceph-compiled > qemu-kvm and qemu-img as downloaded from the Ceph site. > > I can mount the rbd volume outside of qemu/kvm with > a normal rbd map on the same machine, verify the full > partition table structure is there and all the files are there. > > KVM must be doing the rbd map and mount correctly because > I can see the device in question mapped to a /dev/rbd1. > > So I must be dealing with some problem with the format > of the image, only question is what?? ?Libvirt is presenting > the rbd volume to the virtual machine as /dev/vda > and it was installed on a classic virtual machine (i.e. vda > was pointing to a partition on a local hard disk) with the boot > sector on the first sector of vda. > > Any help is appreciated. > > Thanks > > Steve Timm > > > > ------------------------------------------------------------------ > Steven C. Timm, Ph.D? (630) 840-8525 > timm at fnal.gov? http://home.fnal.gov/~timm/ > Fermilab Scientific Computing Division, Scientific Computing Services Quad. > Grid and Cloud Services Dept., Associate Dept. Head for Cloud Computing > _______________________________________________ > ceph-users mailing list > ceph-users at lists.ceph.com > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > > > > ------------------------------------------------------------------ Steven C. Timm, Ph.D (630) 840-8525 timm at fnal.gov http://home.fnal.gov/~timm/ Fermilab Scientific Computing Division, Scientific Computing Services Quad. Grid and Cloud Services Dept., Associate Dept. Head for Cloud Computing
 |