today I renamed the Label of vswitch1 for enabling vmotion,
but after that I found that the virtual machines are not showing in vm port group.
They are gone.
How can I get the vm's back.
Note:- VM are on network, working fine. If I check then under ESX's virtual machine, they are showing there.
Assuming you have tried to change the vSwitch Label back again.
Therefore have you tried vSphere Networking Rollback from the DCUI to reset the management interfaces on the host?
As you said, the VM continues to run but the label is gone so in the client you do not see the network configured for the VM so have to change it as per the above,
I hope this solves your problem