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  • 1.  Dormant VMs stealing resources??

    Posted Feb 08, 2009 10:01 PM

    Using Latest ESXI, we are getting good performance out of HP servers with 3-5 VM's on each. Question is, if I have a couple of 'Dormant' VM"s on a host, that are rarely used, without any resource pools created, looking at the resource allocation, it is spread evenly between all VM's, even the dormant ones, for example, with 5 VM's, each gets a 20% cut. Does this mean the 2 dormant (turned off) VM's are causing the 3 others to take a lower share than if I had deleted those VM's, which would give each running VM a 33% cut instead??

    Hope this makes sense.



  • 2.  RE: Dormant VMs stealing resources??

    Posted Feb 08, 2009 10:18 PM

    Resources are not allocated on a strictly proportional basis. If a VM does not ask for resources, it will not use them. Idle VMs will consume SOME resources (to service interrupts, run background tasks, etc.), but in general, won't take much.

    Ken Cline

    Technical Director, Virtualization

    Wells Landers

    TVAR Solutions, A Wells Landers Group Company

    VMware Communities User Moderator



  • 3.  RE: Dormant VMs stealing resources??

    Posted Feb 08, 2009 10:23 PM

    Without a defined resource pool, all VMs are in the "parent" resource pool. This means that each VM gets an equal "share" of the cluster's resources. If you have no reserves, limits, or shares defined, then as a VM needs more resources it'll have access to whatever's not being used within the cluster by the other VMs - "expandable reservation". If there is contention for memory resource, then one of the 3 memory management techniques will come into play. When a VM is turned off, even if it has a reservation for memory or CPU, the other VMs will be able to use all the resources in the cluster. Once it's turned on (or power on) then the reservations will come into account.

    Hope this helps, t