Migrating from standard vSwitches to distributed vSwitches has a lot of advantages. I have listed a few below.
- Central management for all host in the vDS
- Uniform configuration for all hosts
- Easily add new port groups
The one major disadvanatage is if vCenter is down you cannot manage the vDS.
To use vDS you will need to have Enterprise or Enterprise Plus VMware licences.
To migrated from vSS to vDS go to networking in the VMware web client and right-click on vCenter server and go to distributed switch.
Give the vDS a suitable name
Select the version of ESXi you have in production if you select a newer version than you have running in vCenter the host will show as incompatible
The defualt number of uplinks is 4. I only had two uplinks so I changed this to two. 
After the vSwitch has been created I usually add a port group for management and vMotion VMkernel networks.
To migrated from the standard switch right-click on the vDS and go to Add and Manage Hosts.
Select add hosts. 
Select the host that you want to add to the vDS
The next page is where you manage the physical uplinks. Click assign uplinks and assign to the vDS. 
Next we can migrate the VMkernel adapters. I only have a management network but this is the same process if you have vMotion or any other VMkernel adapter. Click assign port group and select the relevant port group in my case it was dv_Managment. 
Last step is to migrate VM’s. If you have multiple networks / port groups you migrated each individual VM to its own port group I only have one so I assigned each VM to the same port group. 
Once the task have completed you should now see the Host and VM’s running on the new port group. 
TheSleepyAdmins 