Hi, AFAIK Xen can restart VMs after a reboot of Dom0 (the configuration depends on the xen version I think). This will automatically recover the VMs and eventually OpenNebula will put them from unknown to active.
Cheers Ruben On Mon, May 16, 2011 at 11:55 PM, Piotr Kandziora <[email protected]>wrote: > Hi, > > So, if I restart my physical nodes, all virtual machines after this > operation will be in 'unknown' state. I can then restart them manually and > this works. But in my solution it would be good if this happen without user > intervention (automatic VMs start after nodes restart). > > Is there any good practice? Maybe one should monitor this situation and > after restart physical nodes should be able to run VMs in automatic way > (e.g. hooks invoked when host goes from 'err' to 'on' state)? > > Best regards > Piotr Kandziora > > > On Fri, Feb 18, 2011 at 6:28 PM, Ruben S. Montero <[email protected]>wrote: > >> Hi, >> >> OpenNebula monitors VMs in unknown state. So, if the VMs are restarted, >> OpenNebula should be able to recover those VMs and move them from unknown to >> running. The requirement is to and the id's are preserved at the hypervisor >> level (e.g. autostart i think) >> >> Cheers >> >> Ruben >> >> >> On Fri, Feb 18, 2011 at 6:05 PM, Shi Jin <[email protected]> wrote: >> >>> Thank you for the discussion. >>> >>> Yes, there is definitely a possible problem of out of sync between the >>> host and OpenNebula. >>> For example, after the node power failure, the one status for the VMs >>> would be unknown. If people then deleted the VM, restarting the VM upon >>> power resumption would cause a problem. >>> But this seems to be a more operational problem: just don't delete the >>> VMs on a power failure node. >>> There are many other ways to cause out of sync under existing OpenNebula >>> setup and it is up to the administrator's operation to ensure everything is >>> consistent. >>> >>> Also, starting a power failure VM definitely has the potential problem of >>> disk corruption. But this is the best we can do upon such a tragic >>> situation. One should ask more on why on the earth did the power fail in the >>> first place? The autostart setup would simply ease a little bit of the pain. >>> >>> Shi >>> >>> >>> On Thu, Feb 17, 2011 at 8:42 PM, Manikanta Kattamuri < >>> [email protected]> wrote: >>> >>>> Assume all this is set and the vm's automatically come up after the >>>> servers get online. >>>> would it not create more problems then solve as you one is not in sync >>>> with all the vm states?. >>>> If there are any monitoring tools configured based on one status, will >>>> report failure. >>>> Starting of the vms through oned will not succeed or cause disk >>>> corruption? >>>> >>>> Mani. >>>> >>>> On Fri, Feb 18, 2011 at 4:03 AM, Shi Jin <[email protected]> wrote: >>>> >>>>> Hi there, >>>>> >>>>> Right now, all KVM (I think Xen too but I don't know it for sure) VMs >>>>> are started as a transient libvirt domain using the "virsh create <xml>" >>>>> command. >>>>> There is nothing wrong with it but recently I had a facility wide power >>>>> failure and all VMs running on the node are gone upon the server >>>>> shutdown. I >>>>> had to manually start all the domains that were running at the point of >>>>> failure after power is resumed. Then I thought that if I put the VMs as >>>>> libvirt autostart domains, they will be automatically started upon boot, >>>>> which would save me a lot of manual process. But to do that, I have to >>>>> make >>>>> the VMs persistent libvirt domains using the "virsh define" and "virsh >>>>> start" commands in sequence instead of the single "virsh create". >>>>> >>>>> Is this a good idea? Comments welcome. >>>>> Thanks. >>>>> Shi >>>>> >>>>> -- >>>>> Shi Jin, Ph.D. >>>>> >>>>> >>>>> _______________________________________________ >>>>> Users mailing list >>>>> [email protected] >>>>> http://lists.opennebula.org/listinfo.cgi/users-opennebula.org >>>>> >>>>> >>>> >>> >>> >>> -- >>> Shi Jin, Ph.D. >>> >>> >>> _______________________________________________ >>> Users mailing list >>> [email protected] >>> http://lists.opennebula.org/listinfo.cgi/users-opennebula.org >>> >>> >> >> >> -- >> Dr. Ruben Santiago Montero >> Associate Professor (Profesor Titular), Complutense University of Madrid >> >> URL: http://dsa-research.org/doku.php?id=people:ruben >> Weblog: http://blog.dsa-research.org/?author=7 >> >> _______________________________________________ >> Users mailing list >> [email protected] >> http://lists.opennebula.org/listinfo.cgi/users-opennebula.org >> >> > > _______________________________________________ > Users mailing list > [email protected] > http://lists.opennebula.org/listinfo.cgi/users-opennebula.org > > -- Dr. Ruben Santiago Montero Associate Professor (Profesor Titular), Complutense University of Madrid URL: http://dsa-research.org/doku.php?id=people:ruben Weblog: http://blog.dsa-research.org/?author=7
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