It depends, you can configure a HA setup and have another opennebula gain control of the cloud, and restart the VMs.
-- Join us at OpenNebulaConf2013 <http://opennebulaconf.com> in Berlin, 24-26 September, 2013 -- Carlos Martín, MSc Project Engineer OpenNebula - The Open-source Solution for Data Center Virtualization www.OpenNebula.org | cmar...@opennebula.org | @OpenNebula<http://twitter.com/opennebula><cmar...@opennebula.org> On Thu, Sep 5, 2013 at 3:24 PM, Igor Laskovy <igor.lask...@gmail.com> wrote: > Ok, thanks. And one more: is it true that if I lost front-end host along > with some hypervisor hosts died VMs don't restart on alive hosts? > > > On Thu, Sep 5, 2013 at 1:34 PM, Carlos Martín Sánchez < > cmar...@opennebula.org> wrote: > >> Hi, >> >> On Wed, Sep 4, 2013 at 12:03 PM, Igor Laskovy <igor.lask...@gmail.com> >> wrote: >> >>> One further question - how Fault Tolerance mechanism (via HOST_HOOK) >>> deal with this reservations? Does it reserved some "slots" for VMs recovery? >>> >> >> OpenNebula does not have any kind of reservation scheduling. >> >> >>> If not and if I at every turn manually don't control available resources >>> on hosts those may cause to situation when my automatically recreated VMs >>> will stuck in placement state. >>> >> >> Yes, that may happen. But you still can implement a reservation mechanism. >> I'm sure there are better alternatives, but this is a quick idea: >> >> - Disable half of your hosts. >> - For each enabled host, define a failover_host = <id> attribute in its >> template, pointing to one of the disabled hosts >> - Modify the fault tolerance hook to make it enable the defined failover >> host. >> >> Another quick hack is to create a dummy VM for each VM that you need to >> guarantee that reserved slot, using the requirements and current_vms >> features to deploy it in a host different from the original VM. Then delete >> that VM when the hook recreates the original VM... >> >> >> Regards. >> >> -- >> Join us at OpenNebulaConf2013 <http://opennebulaconf.com> in Berlin, >> 24-26 September, 2013 >> -- >> Carlos Martín, MSc >> Project Engineer >> OpenNebula - The Open-source Solution for Data Center Virtualization >> www.OpenNebula.org | cmar...@opennebula.org | >> @OpenNebula<http://twitter.com/opennebula><cmar...@opennebula.org> >> >> >> On Wed, Sep 4, 2013 at 12:03 PM, Igor Laskovy <igor.lask...@gmail.com>wrote: >> >>> Thank you for reply! >>> >>> One further question - how Fault Tolerance mechanism (via HOST_HOOK) >>> deal with this reservations? Does it reserved some "slots" for VMs >>> recovery? If not and if I at every turn manually don't control available >>> resources on hosts those may cause to situation when my automatically >>> recreated VMs will stuck in placement state. >>> >>> >>> On Wed, Sep 4, 2013 at 12:23 PM, Carlos Martín Sánchez < >>> cmar...@opennebula.org> wrote: >>> >>>> Hi, >>>> >>>> On Tue, Sep 3, 2013 at 1:32 PM, Igor Laskovy <igor.lask...@gmail.com>wrote: >>>> >>>>> Hello all! >>>>> >>>>> I found that this already have discussed not so far from now - >>>>> http://comments.gmane.org/gmane.comp.distributed.opennebula.user/10568 >>>>> >>>>> As understand for now about Memory over-commitment for production I >>>>> can forget ;) >>>>> >>>>> For CPU over-commitment I can only use CPU & VCPU attributes, right? >>>>> >>>> >>>> That's right >>>> >>>> >>>>> If I will, for example, set CPU to 0.2, than host will do only >>>>> reservation of processor time for that VM OR do limit ether, so this VM >>>>> will limited of 1/5 of one physical/logical hardware core? >>>>> >>>> >>>> We enforce the CPU reserved at hypervisor level with cgroups for kvm, >>>> credit scheduler for xen, and the esx cpu scheduler for vmware >>>> >>>> Regards >>>> >>>> -- >>>> Join us at OpenNebulaConf2013 <http://opennebulaconf.com/> in Berlin, >>>> 24-26 September, 2013 >>>> -- >>>> Carlos Martín, MSc >>>> Project Engineer >>>> OpenNebula - The Open-source Solution for Data Center Virtualization >>>> www.OpenNebula.org <http://www.opennebula.org/> | >>>> cmar...@opennebula.org | @OpenNebula <http://twitter.com/opennebula> >>>> >>> >>> >>> >>> -- >>> Igor Laskovy >>> facebook.com/igor.laskovy >>> studiogrizzly.com >>> >> >> > > > -- > Igor Laskovy > facebook.com/igor.laskovy > studiogrizzly.com >
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