Today I received an email from my friend Tom Arentsen (http://blog.arentcs.com/) with some useful info I would like to share. If you don’t know who Tom is, he is one of the latest members of the select club of VMware Certified Design Experts.
Tom was playing in his lab (servers with a single NIC ) and he wanted to migrate from vSwitch to vDS, he realized that when he would do so he would lose connection with the vCenter (and when vCenter is down no changes to the vDS can happen).
He found out that the solution is really easy:
- Normally we set our binding of our vDS to static, because when the vCenter is down everything continues to run normally except that you cannot make any changes.
- In addition to the normal dvportgroups, he created an additional dvportgroup with ephemeral binding and tagged it with the same VLAN ID as the one which is required by vCenter server.
- Ephemeral binding pretty much works the same as the standard vSwitch, so the nice thing of Ephemeral port groups is that administrators can login directly to an ESXi hosts and reconfigure a VM to connect to an ephemeral port group (just like you do with a vSwitch) -> EVEN WHEN VCENTER IS POWERED-OFF.
So bottom-line, the answer to the question “Are we going to implement full vDS or hybrid?” is full vDS.
Ephemeral port groups are a very nice solution for solving this issue, so do the following:
- Don’t use Ephemeral port groups for production networks
- BUT create an ephemeral port groups as a backup for the most critical VLAN’s like your vCenter one.
Test this out for yourself and hopefully you will feel more comfortable going forward with a full vDS design.