On Wed, Nov 26, 2008 at 11:14:51AM -0700, Jim Fehlig wrote: > Daniel P. Berrange wrote: > > On Fri, Nov 21, 2008 at 11:13:04PM +0100, Guido G?nther wrote: > > > >> Hi, > >> I just ran across these oddities when using a bit more libvirt+xen: > >> > >> 1.) virsh setmaxmem: > >> > >> On a running domain: > >> # virsh setmaxmem domain 256000 > >> completes but virsh dumpxml as well as the config.sxp still shows the > >> old amount of memory. Looks as the set_maxmem hypercall simply gets > >> ignored. xm mem-max works as expected. Smells like a bug in the ioctl? > >> > > > > The setmaxmem API is not performance critical, so it sounds like we > > should first try setting it via XenD, and use Hypervisor as the > > fallback instead. > > > > I have a patch for 0.4.6 in suse packages to do just this. Using xend, > you also get the value changed in dom config. Do send the patch to the list & we'll see about applying it... > > > > This is basically a XenD bug. What's happening is that the domain > > has been shutdown, and got most of the way through cleanup, as far > > as the hypervisor is concerned. But something is still hanging around > > keeping the domain from being completely terminated. In this case > > XenD takes the dubious approach of just pretending the domain does > > not exist. So libvirt sees it exists in the hypervisor, but when > > asking XenD for more data, it gets that error. This really really > > sucks. > > > > I spent some time looking into this bug as well. I found that we ask HV > for number of domains and get back more than actually exist. We > subsequently query xend about such domains and get the error message > noted. It turned out being a 'dead domain' memory leak in xen itself. > Jan Beulich plugged the hole and sent patch upstream but I can't seem to > find the relevant c/s now :-(. Anyhow, with Jan's fix I no longer see > these error messages. This seems to be quite a common problem for a number of users. Its good that Xen has a fix now, but if switching to querying XenStore for domain IDs make it work we should do that as a preventative measure in libvirt Daniel -- |: Red Hat, Engineering, London -o- http://people.redhat.com/berrange/ :| |: http://libvirt.org -o- http://virt-manager.org -o- http://ovirt.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: GnuPG: 7D3B9505 -o- F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 :| -- Libvir-list mailing list Libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list