DRS question.

We have recently added a new host to our VMware 5.5 cluster.  Currently, we have turned off DRS to make sure no VM being migrated to the new host.  

Besides turning off DRS at the cluster level, is there a way we can prevent any VM from being moved into the new host?  

We want the DRS option to be available only for the previous hosts to load balance each other until the new host is fully in production.  

Thanks.
nav2567Asked:
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Richardson PortoConnect With a Mentor Senior Infrastructure SpecialistCommented:
You could create a affinity rule to avoid virtual machines to run on the new host. Take a look here for additional details: https://pubs.vmware.com/vsphere-51/index.jsp?topic=%2Fcom.vmware.vsphere.resmgmt.doc%2FGUID-D2E5FBE2-E4BF-48B1-BF02-BF37AE9D5F21.html
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Andrew Hancock (VMware vExpert / EE MVE^2)Connect With a Mentor VMware and Virtualization ConsultantCommented:
Put the Host in maintenance mode will stop any VMs being migrated to it.
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nav2567Author Commented:
Andrew, if I put the new host in maintenance mode, whatever VMs running in the new host will still be functioning, right?
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Andrew Hancock (VMware vExpert / EE MVE^2)VMware and Virtualization ConsultantCommented:
No, they will be moved.

What are you trying to do?

If the host is not fully in production, it should not have been added to the cluster! It should be tested first, and then moved finally into the Cluster for Production.

You will also need to disable HA, because in the event a Host Crashes, VMs will be restarted on the new host.

Also remember DRS is not a load balancer, it moves a VM, if the current host cannot satisfy it's resources it requires e.g. CPU and Memory.

and if you leave DRS ON, and set to MANUAL, no VMs are going to move anywhere, unless you manually do something.
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nav2567Author Commented:
Sorry that I did not make the question clear.  

We add a new host to a cluster, move a group of VMs into this new host.  We do not want any more VM being moved as a result of DRS.

Besides turning off DRS at the cluster level which impacts the previous hosts in the cluster, is there a better way to do it?

Thanks.
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Andrew Hancock (VMware vExpert / EE MVE^2)VMware and Virtualization ConsultantCommented:
What we do, if you are trying to build confidence in your new host, is we set DRS ON and MANUAL....

So, this will stop any VMs automatically moving around your cluster, and then run the DRS review, manually move VMs using vMotion (a human does this) to satisfy DRS conditions and CPU and Memory pressure - if any exists...

 and we then only move low priority VMs to test this new host, until we are happy all is working well, to set DRS back to AUTOMATIC, Aggressive.

How long you test and build confidence in this new host is based on your Test Plan.
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Richardson PortoSenior Infrastructure SpecialistCommented:
Another option, instead of disable DRS, is let it Fully Automated and change the migration threshold to a level different than the level 3 (default). For example, changing the migrating threshold to level 1 (conservative) will only apply recommendations that must be taken to satisfy cluster constraints like affinity rules and host maintenance.
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nav2567Author Commented:
Thanks, guys.  

I am not familiar.  Would you provide instruction on how to set DRS to different level?  

Thanks.
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Richardson PortoSenior Infrastructure SpecialistCommented:
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Andrew Hancock (VMware vExpert / EE MVE^2)VMware and Virtualization ConsultantCommented:
set to manual.
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nav2567Author Commented:
For of all, thanks for your useful suggestions.

Currently, there are 5 VMs in the new host and DRS is set to off.  

To see the threshold settings, I will have to enable DRS again.  Other VMs will be moved to the new host as it has more resources.  

Is there a way that I can enable DRS but exclude the new host to be involved?

If I enable DRS, set automation level to MANUAL, migration threshold to MEDIUM, I think no migration will occur, right?  What is the different between doing this and disable DRS?
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Richardson PortoSenior Infrastructure SpecialistCommented:
If I enable DRS, set automation level to MANUAL, migration threshold to MEDIUM, I think no migration will occur, right?
Yes, only recommendations will be generated but no automatic migration will occur.

What is the different between doing this and disable DRS?
The difference is that on DRS enable in manual mode, the DRS will evaluate the resource utilization of your cluster and made migration recommendation. With DRS disable, no evaluation or recommendation will be generated.

Again, I believe that the best scenario for you is create Affinity Rules, that will allow DRS run in Fully Automated mode and avoid unwanted virtual machines be migrated to the new host.
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Andrew Hancock (VMware vExpert / EE MVE^2)VMware and Virtualization ConsultantCommented:
Disable DRS and it does not function.
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patronConnect With a Mentor Commented:
if u want host to be balanced except this new host so get this host out  from cluster till it is ready to move in production
or keep in maintenance mode till u get it ready for balanced cluster
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