How to allow multiple users login to a MAC PRO without interruption?

Question

I have a mac pro, which runs Yosemite, (2013 module) to be used as a server. However, I have difficult to let multiple users to use the mac simultaneously.
Objective:
    One person uses the mac directly on his desktop, while the others to login remotely though VNC from PC (win 7/Linux).
    The users have their own workspace, and they will not interrupt each other.
What I tried:
    I created two mange accounts on the MAC.
    Account 1 was used to directly login on the mac desktop.
    Account 2 was used to login to the mac from a PC though VNC. (I also tried this from a Centos workstation with the Tiger VNC viewer)
Problem:
When account 2 is login, the location monitor will automatically change to that account as well. Both accounts shared exactly the same screen, mouse & keyboard actions. It is impossible to let multiple users to use the MAC pro simultaneously without interruptions.
If I use "hdiutil attach" to mount a dmg file though SSH with account 2, the folder will automatically show in the local desktop login with account 1.
Question:
I read something about the "Per-user screen sharing". It says, "You can remotely log into a Mac with any user account on that computer and control it, without interrupting someone else who might be using the computer under a different login." Is it possible to do this from a PC or Linux client?
If the problem is simply due to the poor functionality of the build-in VNC service in Yosemite, I appreciate your help to suggest some other decent VNC server for Yosemite. I know the Vine Server (OSXvnc), but I failed to install it on the mac because it is incompatible with the Yosemite.
Does the SSH is supposed to work in this way in OSX? I mean the local account can see the folder mounted by another account though SSH.
If any specific version of Yosemite is required to allow multiple users to access a mac simultaneously? Just as the win 7 professional allow only one user to login in at each time. But with the remote desktop server of windows, multiple users are able to use the same computer at the same time without any problem.
If you familiar with any of the above questions, please help. Any comments and suggestions are appreciated.
I know the best way to get the solution is to direct call the apple support. However, it is really not easy to call them. Because it always results with long waiting time and then the people pick up the phone will transfer my call to an expert who will make me to describe the problem again.
Since I'm not interested in the technique details of all the problems, it is also grateful if you would provide a direct instruction to let me setup the computer for the purpose.
Thanks you very much for your kindly help.

Answer 1

I cannot help with the screen sharing, although I have just tried it with a RealVNC client on an iPad and it seemed to work OK.
However on the disk showing on all users desk tops have you unchecked the "ignore ownership on this volume" check box? You can check the drives permissions with CMD i command.