Virtual Distributed Switch called as vDS is a feature of Enterprise Plus package of the Vsphere Suite. It is managed by vcenter server. It is used for standard settings across all the hosts in a cluster. Even if the VM is moved the port settings and all the configurations are moved with the VM. There are two copies of the configuration
One copy is stored in the vcenter sql database and a local copy is stored in the /etc/vmware/dvsdata.db on the local esxi host. The cached copy is updated every five mins.
To check the local configuration on a host, login to the console and type
you can extract the information using the following command
./net-dvs > /tmp/dvinfo.txt
and read the info.txt file.
some of the vds info is also present in esx.conf located at /etc/vmware
In a broad sense then you can take a virtual distributed switch (vDS) as a template. But a template to what. It can be considered to as template to vSwitches. If you look at the architecture of a vSphere Distributed Switch then you see two sections one is called Control plane and the other is called I.O plane. Now the control plane is management part and deals with NIC teaming, management network, LANs, PVLANs etc. These setting are same on all the hosts and is cluster-wide. The I/O plane is where the switching takes place.
You can say the I/O plane has hidden Virtual Switches (vSS). The vSS links to uplinks and vshield zones and other networking API work at this I.O plane. As there is this vSS layer the data is handled here only and not moved to the vcenter server. If vcenter server goes down the data transfer wont stop but its just we wont be able to add new dvport groups and change the settings.
You can read this guide here from vmware. I will be posting more on virtual distributed switch features and some policies later in my posts.