Yanto,
You do not need to create a VAP. Here is what you need to do:
1. Find out what ap-group you want your mesh aps to be in. It can be in the same ap-group as your other APs. If it is in the same ap-group it will also broadcast the same wireless lans while doing mesh at the same time. You can create a separate ap-group if you only want them to mesh together but NOT broadcast any wireless lans.
2. Navigate to your ap-group - There are only two mesh profiles that are necessary to do mesh and there is not much to do with them. Go to Configuration> Wireless> AP Configuration. If you want to create a new ap-group so that they just mesh, and do not broadcast any wireless lan, click on NEW to create a new ap-group. If you want to use an existing ap-group, edit the ap-group that you want your mesh devices to be in by clicking on that ap-group.
3. Create your Profiles - To do mesh, at minimum you need a mesh radio profile and a mesh cluster profile. There is normally a default mesh radio profile and that is created by default, so you really only have to create the mesh cluster profile. Navigate to your ap-group like in step 2 and expand mesh. Click on the mesh radio profile just to make sure it exists. There is normally a default mesh radio profile in there. Now, click on Mesh Cluster. In the right pane where you see "Add a Profile", click on the dropdown and click on new. In the box to the right, name your mesh cluster anything and click on Add. You should see your new mesh cluster. Click on Apply in the lower left hand corner. You should see a warning that says that the mesh configuration will not take effect unless you re-provision APs-- That is just a reminder. In this example the defaults for the mesh profiles is sufficient.
4. Provision Your access Points - Your access points initially must be up (wired) and connected to the controller so that you can provision them. If you tried to provision other mesh APs and they cannot be seen by the controller, you will need to use the console cable to reset them, and then plug them in wired, so that they can be seen by the controller. If your AP can be seen by the controller, navigate to Configuration> Wireless> AP Installation. You should first provision the Mesh Point (the far end of the mesh), so that you can plug it into only power and allow it to boot up. Select the AP that you want to be provisioned as the Mesh Point and click on Provision. Make sure the ap-group selected is the one with the mesh profiles you created in step 3. All the way at the bottom of the page, there is a Mesh Role paramter. Change that to Mesh Point. Click on Apply and Reboot. When it looks like the access point is rebooting, remove it fom the ethernet and plug it into only power so that it can boot up. You now want to provision your Mesh Portal (wired) AP. Go back to Configuration> Wireless> AP Installation. Find the AP that you want to provision as your Mesh Portal; put a check mark in the box next to it and click on Provision. Make sure the ap-group parameter is the ap-group of the mesh profiles that you created in step 3. Go to the bottom of the page and change the Mesh Role parameter to Mesh Portal. Click on Apply and Reboot. You should leave the AP connected to the ethernet, because a Mesh Portal AP is the one that is plugged into the physical infrastructure.
5. Your mesh point (the far end AP) relies on the mesh portal access point being up to reach the controller. Wait a few minutes to make sure the mesh portal is up on the controller. After that is up on the controller you should see the mesh point a few minutes later.