On Sun, Nov 07, 2010 at 08:53:32PM +0800, Guangya Liu wrote: > Hi, > > > > We are encountering a problem of race conditions for getting VNC port > when VM start up. > > > > In a very powerful hypervisor, if we try to start up more than 1 VM > concurrently, then there might be some VMs failed to start up due to VNC > port confilict. > > > > We searched libvirt bugs and found that some one report the problem and > we have give a fix, but the fix can not resolve the problem. > > > > http://osdir.com/ml/libvir-list/2010-05/msg00530.html > > https://build.opensuse.org/package/view_file?file=vnc-race-3.patch&packa > ge=libvirt&project=Virtualization:openSUSE11.3 This patch is already merged in current GIT repos. > The bitmap test-and-set operation is not atomic, so that there still is > a time-window in which a VNC port could be reserved for two caller. The virBitmap APIs for getting & setting don't need to be atomic, because they are only called when the QEMU driver mutex is held, which ensures serialization of VM startup. Regards, Daniel -- |: Red Hat, Engineering, London -o- http://people.redhat.com/berrange/ :| |: http://libvirt.org -o- http://virt-manager.org -o- http://deltacloud.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