JDMils_Interact
Enthusiast
Enthusiast

Why is my cluster DRS rule not working?

I would like to "pin" a powered-off virtual server to one host in my cluster- this is for replication purposes as we are only replicating the one host to the DR site. I created the DRS rule, checked it and it is setup correctly, however the virtual server is migrating around the different hosts with no regards for the rule I setup. I have tried "Must" & "Should" rules and they both do the same thing.

I would thus like to confirm that DRS Must & Should rules only work on powered on virtual servers?

vCenter is V6.0 Build 7504637

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scott28tt
VMware Employee
VMware Employee

@JDMils_Interact 

I think that is the expected behaviour, DRS considers placement at power on.

 


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NathanosBlightc
Commander
Commander

In some critical circumstances affinity / anti-affinity rules can be ignored, for example in cases of VM-Host affinity rules, HA can disregard them because of temporary not enough resources, or even Storage DRS rules are ignored in evacuation recommendations.

In case of DRS Affinity rules VMware mentioned: "When you add or edit an affinity rule, and the cluster's current state is in violation of the rule, the system continues to operate and tries to correct the violation. For manual and partially automated DRS clusters, migration recommendations based on rule fulfillment and load balancing are presented for approval. You are not required to fulfill the rules, but the corresponding recommendations remain until the rules are fulfilled."

So I guess it's a normal behavior, because DRS tries to satisfy virtual machines that are recently turned-on, regardless of affinity rules.

Please mark my comment as the Correct Answer if this solution resolved your problem
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berndweyand
Expert
Expert

yes thats a normal behaviour.

the vm is only registered to the "wrong" host. on startup drs will check the rules and places the vm on the host you configured.

but you can vmotion the offline vm to this host and it will stay there

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