I feel a little confused about this:
For example, I have 2 ESXi servers (server 1 and server 2) on server 1 i create a vSS with vmkernel adapter, on server 2 I also create another vSS with vmkernel adapter.
Ok now the question: if I would create a vDS and then make connection with hosts, can I create only 1 vmkernel adapter insead of creating 2 of them (in vSS case)?
I'm asking because I don't see the profit for using vDS in this case.(the only profit I see is that it will be easier to manage 1 adapter instead of managing 2 adapters, am I right?)
Or maybe is there any of other application of vDS in this case?
vDS does give you a centralised Control Plane to manage configuration of vDS in terms of configuration/management etc.
But when it comes to managing VMKernel Adapter vmk# (Management, vMotion, FT logging, VSAN etc...) it's still per host basis. Same thing is for Physical Adapter management (VMNICs) which also needs to be done per host basis.
so if you have 2 hosts or let's say 100 hosts, after creating vDS and attaching those hosts with vDS, if you want to migrate existing VMkernel Adapters or create new ones. it still needs to be done per host basis, To make this process simple, we have a wizard,
Right click on vDS -> Add and Manage hosts -> Manage host networking -> select all those hosts where you want to do some vmkernel adapter or physical adapter management, and follow the wizard. it makes thing very simple.
Let's take an example, I want to manage my VMNIC assignment to appropriate uplinks in vDS and also I want to create a vmk for vMotion in all my vDS attached hosts. I can make use of vSphere Web Client and go with Manage host networking wizard, and during the wizard I would select 'Configure identical networking settings on multiple hosts' and go about selecting one of the hosts as Template host, do desired configuration on it and click on 'Apply to All' (see following documentation link)
vSphere 5.5 Documentation Center
As Narendra fairly stated VDS gives you centralized management for Port Groups, but physical and virtual adapters still have to be managed manually.
From the daily operations perspective I don't believe the "Configure identical networking settings on multiple hosts" option will help you much. Even though it lets you replicate the same network settings (including VMkernel) across all hosts, it asks you to specify IP addresses for all hosts and all VMkernel adapters, including all existing ones. There is no option to specify IP address only for the new VMkernel adapter. As a result, you are forced to re-type the same IPs for all existing host VMkernel adapters across all hosts as well. One typo and if you're using IP storage, it can cause serious issues. So I wouldn't recommend using that.
If you have some scripting experience you can use PowerCLI instead. There is a New-VMHostNetworkAdapter cmdler, which you can use in a simple script to add VMkernel adapters to the hosts as required.
Create a VMkernel adapter on hosts associated with a distributed switch to provide network connectivity to the hosts and to handle the traffic for vSphere vMotion, IP storage, Fault Tolerance logging, and Virtual SAN. You can create VMkernel adapters on multiple hosts simultaneously by using the Add and Manage Hosts wizard.
You should dedicate one distributed port group for each VMkernel adapter. One VMkernel adapter should handle only one traffic type.
1 In the vSphere Web Client, navigate to the distributed switch.
2 From the Actions menu, select Add and Manage Hosts.
3 Select Manage host networking and click Next.
4 Click Attached hosts and select from the hosts that are associated with the distributed switch.
5 Click Next.
6 Select Manage VMkernel adapters and click Next.
7 Click New adapter.
The Add Networking wizard opens.
8 On the Select target device page of the Add Networking wizard, select a distributed port group.
9 On the Port properties page, configure the settings for the VMkernel adapter.
It won't let you create them simultaneously. You will still have to create them one at a time.