If there is a partition table on the device, you need to get Linux to scan the partition table and build the sub-devices. Try running "kpartx -a /dev/rbd0" to create the devices. Since you have LVM on the second partition, ensure that it is configured to not filter out the new partition device and you should be able to get the device mapper to add the logical volumes contained within the group. On Thu, Aug 25, 2016 at 1:31 PM, Deneau, Tom <tom.deneau@xxxxxxx> wrote: > If I have an rbd image that is being used by a VM and I want to mount it > as a read-only /dev/rbd0 kernel device, is that possible? > > When I try it I get: > > mount: /dev/rbd0 is write-protected, mounting read-only > mount: wrong fs type, bad option, bad superblock on /dev/rbd0, > missing codepage or helper program, or other error > > The rbd image when viewed from the VM has a /dev/vda disk with 2 partitions > > Number Start End Size Type File system Flags > 1 1049kB 525MB 524MB primary xfs boot > 2 525MB 12.9GB 12.4GB primary lvm > > I wanted to view it thru the /dev/rbd0 mount because on one of my systems, > the VM is not booting from the image. > > -- Tom > _______________________________________________ > ceph-users mailing list > ceph-users@xxxxxxxxxxxxxx > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com -- Jason _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com