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  • 1.  Distributed switch running out of ports

    Posted Jun 21, 2011 04:26 PM

    Hello all,

    Having an odd problem. Attempting to migrate a VM across two ESXi hosts, build 4.1/348481, in a 4 node cluster, fails with the message below.  I have confirmed a total of 3082 ports in use across all DvSwitches in this VirtualCenter, which is well below the maximum limit of 6000. All PG's are set to epheremal binding, and the default setting for default timeout for locked dvPorts has not been changed. There are also some standard vSwitches within this VirtualCenter. I am also getting the error message listed when attempting to connect the VMs interface-

    "Cannot create DVPort 3914 of vDS vmguest_dvs on the host xxx.xxxx.xxxx  An error occurred during host configuration."

    What's strange, It is possible to move between another host in the same cluster, however attempting to move from this host to the other two fail. If anyone's encountered this problem before, please advise. Thanks..



  • 2.  RE: Distributed switch running out of ports

    Posted Jun 21, 2011 06:51 PM

    Well,

    I think we've isolated root cause but not a solution. It appears that exceeding 1016 ports might cause the issue...thanks to Dave Hill for documenting on his blog.

    http://www.virtual-blog.com/2011/05/memory-problems-occur-when-a-host-uses-more-than-1016-dvports-on-a-vds/

    The KB article doesn't list a solution except to move VM's to another host - really? We've opened a BCS case so I will post results if found.



  • 3.  RE: Distributed switch running out of ports

    Posted Jun 21, 2011 07:16 PM

    You are not really using 1016 vSwitch ports concurrently on a single host, do you?

    I guess the problem is caused by using ephemeral binding in your case. You should limit ephemeral bindings to these VMs that really need it, and otherwise stick with the default (dynamic binding). With dynamic binding only the ports that are currently in use will exist on the host's dVS proxy switch, so you will probably never reach the 1016 ports limit.

    Andreas

    - VMware Front Experience Blog



  • 4.  RE: Distributed switch running out of ports

    Posted Jun 21, 2011 07:32 PM

    Thank you for your reply, Andreas. A single host? No, currently 1288 across 4 hosts, but unless someone has a better answer this is our best/only info thus far, and seems to directly related to the underlying issue.

    Isn't static binding the default? Unless there's a way to modify this in VC, it is in our environment. From what I've read on dynamic binding you could potentially oversubscribe ports and make the problem worse, hence using ephemeral by design....Thanks.



  • 5.  RE: Distributed switch running out of ports

    Posted Jun 22, 2011 06:25 AM

    You are right, the default is "Static binding". I didn't remember that correctly.

    For a brief explanation of the three binding methods see e.g. here:

      http://www.vmskills.com/2010/10/static-dynamic-and-ephemeral-binding-in.html

    If you really use that much ports you may consider using dynamic binding.

    However, if your vCenter machine is a VM I would configure it with ephemeral binding to remove any circular dependencies.

    Andreas

    - VMware Front Experience Blog