Re: [ovirt-users] Spam Cluster Polcies

From: "Jiri Moskovcak" <jmoskovc(a)redhat.com&gt; To: "Gilad Chaplik" <gchaplik(a)redhat.com&gt;, "Maurice James" <mjames(a)media-node.com&gt; Cc: "users" <users(a)ovirt.org&gt; Sent: Monday, June 30, 2014 3:57:29 PM Subject: Re: [ovirt-users] Spam Cluster Polcies On 06/30/2014 01:53 PM, Gilad Chaplik wrote: > ----- Original Message ----- >> From: "Maurice James" <mjames(a)media-node.com&gt; >> To: "users" <users(a)ovirt.org&gt; >> Sent: Friday, June 27, 2014 1:20:23 AM >> Subject: [ovirt-users] Spam Cluster Polcies >> >> Can someone explain the cluster policies to me? The explanation at >> http://www.ovirt.org/Features/Even_VM_Count_Distribution is not quite >> clicking for me. >> >> >> >> * HighVMSCount - Maximum VM limit. Exceeding it qualifies the host as >> overloaded. ( Understood ) > > minimal #vms on host to enable the module (i.e worst host should have more > than HighVMSCount vms). > >> * MigrationThreshold - defines a buffer before we start migrating VMs >> from the host ( Not quite grasping. If my High limit is 5 does this >> mean >> that it will only begin to move VMs when the count reaches 10? ) > > don't think that there's any relation with "HighLimit". > It means that migration will happen only if there is a difference of X vms > or more between worst host (source host) to destination host. > > let say that you have 2 hosts. one has 10 vms and the second 8. if the > threshold is 3, no migration will happen (10-8 !> 3). - exactly > >> * SPMVMCountGrace - defines how many slots for VMs should be reserved >> on >> SPM hosts (the SPM host should have less load than others, so this >> variable defines how many VM less it should have) ( Does this mean >> that >> if I have a host with only 3 VMs the SPM will 3 VMs minus the >> SpmWmGrace? Or is this HighVmCount minus SpmVmGrace count?) > > you're right, the SPM host will have current + grace VMs in terms of module > calculations. > I think that this is problematic, it is likely to be selected as worst host > candidate and that's not the wanted behavior iiuc > imo, we should subtract (-) in overloaded hosts and add (+) in > underutilized. - I think it's correct as it is, if the SpmVmGrace+currentVms > HighVmCount it is overutilized and should be freed if possible.

--J > > @Jirka? > >> >> >> >> _______________________________________________ >> Users mailing list >> Users(a)ovirt.org >> http://lists.ovirt.org/mailman/listinfo/users >>