Hello I have a simple question. Can I update libvirt RPM while KVM guest OS on RHEL5 is running. Background When I run rhn_register, then rhn-virtualization-host RPM was installed by RHN. And then libvirt-python was also installed from the RHN. The libvirt-python RPM has a dependency with libvirt. And the dependency was not only the RPM file name, and also specific RPM versions as well. # rpm -qR libvirt-python /usr/bin/python (snip) libssl.so.6()(64bit) libvirt = 0.8.2-15.el5　<== libvirt.so.0()(64bit) So the libvirt from RHEL5.5 was updated to libvirt from RHEL5.6 by this accident. If nothing was happen, I don't care. But after the force libvirt update, I couldn't do attach-disk. 　error : Failed to attach disk error : internal error missing disk device alias name for hdc Now I would like to confirm from the authority that libvirt update while running guest os is supported or not. If supported, then these messages indicated something going wrong. If not, I can ignore it. Regards, Masanari