An administrator is migrating 135 virtual machines from a vSphere Standard Switch to a vSphere
Distributed switch. The migration reports an error and only some of the virtual machines are
transferred.
What is causing the error to occur?
A.
The vSphere Distributed Switch was created with a single, default port group.
B.
The switch has become disconnected from an ESXi host.
C.
The port group on the vSphere Distributed Switch was not configured with an Elastic port
binding.
D.
The virtual machine that failed to transfer did not have a network adapter.
Explanation:
C. must be the answer here. It takes care of automatically increasing AND decreasing the number of ports needed for all VM’s.
default is 128
C – not exist – Elastic port binding
exist in VDS
Static binding
Dynamic binding
Ephemeral binding
http://blogs.vmware.com/vsphere/2012/04/demystifying-configuration-maximums-for-vss-and-vds.html
C does not exist. It would be Elastic port allocation. Each port group is limited to a default 128 virtual ports so if there is only one port group there aren’t enough virtual ports to accommodate 135 VMs.
A!
No such thing as “elastic port binding.” It gets you confused with “elastic port allocation.”
http://pubs.vmware.com/vsphere-51/index.jsp?topic=%2Fcom.vmware.vsphere.networking.doc%2FGUID-FCA2AE5E-83D7-4FEE-8DFF-540BDB559363.html
Hi,
this question is confusing. When I create a DVswitch, in web client, and select create a default port group, the group is created with Elastic port allocation and Static Binding with 8 ports.
If I do the same from windows client, the number of ports is 128 but if I check the port allocation settings, from web client, it is set to elastic.
This implies that the default port group allows for port number to increase dynamically.
Could it be that C should be Elastic port Allocation instead of Elastic port binding?
If it’s worded as “… was not configured with Elastic port allocation”, then the answer would definitely be ‘C’.
‘A’ makes no sense anyway… When you use “Migrate VM to Another Network” in vSphere Web Client (or “Migrate Virtual Machine Networking” in vSphere Client), the migration wizard gives you a choice of Source Network (in this case, standard v-switch port group) and Destination Network (in this case, DVS port group).
Whether there’s one port group on DVS or more, it does not matter. It doesn’t matter either whether it’s “default” or not. By the way, when DVS is created, the only “default” port group is DVUplinks. So ‘A’ cannot be a correct answer by any stretch of imagination.
Correction: by default, a “dvPortGroup” is created with 128 ports pre-allocated but is set for “Elastic” port allocation.
Turns out that the default number of **pre-allocated** ports on DVS depends on what vCenter client – C# or Web Client – is used to create DVS ! If C# – the number is 128 per port group, if Web Client – 8.
Regardless, in both cases the port allocation by default is set to ‘Elastic’ (visible only in Web Client) meaning that the number of ports can be dynamically increased up to 8192 (the max setting for the “Number of ports:” counter in vCenter client).
The fact that the type of port allocation (Elastic vs. Fixed) is not displayed in C# Client may suggest this can be a question for previous vSphere versions for which the answer ‘A’ could be correct. In the context of VCP550 exam however it is clearly the wrong one.
I agree that the answer is A. Even if C. was Elastic Port Allocation, it will only expand the port group to 128. You must create an additional port group on the DVSwitch in order to migrate 135 VMs.
After checking my Datacenter, there doesn’t seem to be a 128 port limit for a port group. However, I have seen instructions from VMware that say you must create the same or more number of ports on a Distributed switch before you migrate vms from a vswitch. That would still make A the answer. I would like to find more difinitive documentation though.
I believe the answer is A, because it references a single, default port group. I have seen migrations fail many times because port groups are missing on the target.
A : The vSphere Distributed Switch was created with a single, default port group.