Re: [libvirt] [libvirt-users] Libvirtd running as root tries to access oneadmin (OpenNebula) NFS mount but throws: error: can’t canonicalize path

On 4/12/2016 5:08 PM, John Ferlan wrote: > Having/using a root squash via an NFS pool is "easy" (famous last words) > > Create some pool XML (taking the example I have) > > % cat nfs.xml > <pool type='netfs'> > <name>rootsquash</name> > <source> > <host name='localhost'/> > <dir path='/home/bzs/rootsquash/nfs'/> > <format type='nfs'/> > </source> > <target> > <path>/tmp/netfs-rootsquash-pool</path> > <permissions> > <mode>0755</mode> > <owner>107</owner> > <group>107</group> > </permissions> > </target> > </pool> > > In this case 107:107 is qemu:qemu and I used 'localhost' as the > hostname, but that can be a fqdn or ip-addr to the NFS server. > > You've already seen my /etc/exports > > virsh pool-define nfs.xml > virsh pool-build rootsquash > virsh pool-start rootsquash > virsh vol-list rootsquash > > Now instead of > > <disk type='file' device='disk'> > <source file='/var/lib/one//datastores/0/38/disk.0'/> > <target dev='hda'/> > <driver name='qemu' type='qcow2' cache='none'/> > </disk> > > Something like: > > <disk type='volume' device='disk'> > <driver name='qemu' type='qemu' cache='none'/> > <source pool='rootsquash' volume='disk.0'/> > <target dev='hda'/> > </disk> > > The volume name may be off, but it's perhaps close. I forget how to do > the readonly bit for a pool (again, my focus is elsewhere). > > Of course you'd have to adjust the nfs.xml above to suit your > environment and see what you see/get. The privileges for the pool and > volumes in the pool become the key to how libvirt decides to "request > access" to the volume. "disk.1" having read access is probably not an > issue since you seem to be using it as a CDROM; however, "disk.0" is > going to be used for read/write - thus would have to be appropriately > configured... > Thanks John! Appreciated again. No worries, handle what's on the plate now and earmark this for checking once you have some free cycles. I can temporarily hop on one leg by using Martin Kletzander's workaround (It's a POC at the moment). I'll have a look at your instructions further but wanted to find out if that config nfs.xml is a one time thing correct? I'm spinning these up at will via the OpenNebula GUI and if I have update for each VM, that breaks the Cloud provisioning. I'll go over your notes again. I'm optimistic. :)