On Tue, Apr 18, 2017 at 7:48 PM, Nelson Lameiras < nelson.lamei...@lyra-network.com> wrote:
> hello, > > When putting a host on "maintenance mode", all vms start migrating to > other hosts. > > We have some hosts that have 60 vms. So this will create a 60 vms > migrating simultaneously. > Some vms are under so much heavy loads that migration fails often (our > guess is that massive simultaneous migrations does not help migration > convergence) - even with "suspend workload if needed" migraton policy. > > - Does oVirt really launches 60 simultaneous migrations or is there a > queuing system ? > - If there is a queuing system, is there a way to configure a maximum > number of simultaneous migrations ? > > I did see a "migration bandwidth limit", but this is quite what we are > looking for. > What migration policy are you using? Are you using a dedicated migration network, or the ovirtmgmt network? > > my setup: > ovirt-engine +hosted engine 4.1.1 > hosts : centos 7.3 fully updated. > > for full context to understand this question : 2 times in the past, when > trying to put a host in maintenance, host stopped responding during massive > migrations and was fenced by engine. It's still unclear why host stopped > responding, but we think that migrating 60+ vms simultaneously puts a heavy > strain on storage ? So we would like to better control migration process in > order to better understand what's happening. This scenario is "production > only" since our labs do not contain nearly as much vm with such heavy > loads. So rather than trying to reproduce, we are trying to avoid ;) > If you could open a bug with relevant logs on the host not responding, that'd be great. Live migration doesn't touch the storage (disks re not moving anywhere), but it does stress the network. I doubt it, but perhaps you over-saturate the ovirtmgmt network. Y. > > cordialement, regards, > > <https://www.lyra-network.com/> > Nelson LAMEIRAS > Ingénieur Systèmes et Réseaux / Systems and Networks engineer > Tel: +33 5 32 09 09 70 <+33%205%2032%2009%2009%2070> > nelson.lamei...@lyra-network.com > www.lyra-network.com | www.payzen.eu <https://payzen.eu> > <https://www.youtube.com/channel/UCrVl1CO_Jlu3KbiRH-tQ_vA> > <https://www.linkedin.com/company/lyra-network_2> > <https://twitter.com/LyraNetwork> > <https://payzen.eu> > ------------------------------ > Lyra Network, 109 rue de l'innovation, 31670 Labège, FRANCE > > > _______________________________________________ > Users mailing list > Users@ovirt.org > http://lists.ovirt.org/mailman/listinfo/users > >
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