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 >
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