[deanhills]

Hey experts, I need help.I am holder of VPS9.I have used command " sudo reboot " to reboot VPS.Now i am getting error " Connection Refused " on connecting to server.I know i should ask staff team for help, but i am asking here so that i will not use these type of commands in future because VPS-9 does not have control panel to manage it self.I don't want to disturb staff.So...Should i use these (reboot, sudo shutdown -h now) reboot commands in future?
For now @Administrators please check what is problem?

Further to @"Hidden Refuge" question - I Googled this and looks as though this is known to happen to Ubuntu.  I realize your Ubuntu is more up to date than the example below, but maybe there are elements of the same problems in it.  Quite a number of the examples in the discussion below experienced problems with reboot after an update - something to do with changes in the SSH configuration that causes you to disconnect.
https://askubuntu.com/questions/483670/w...-04-server

Looks as though the most secure way to do this is to ask the staff to reboot the VPS from the management panel.  

Here's another article about Ubuntu 16 reboot disconnect problems:
https://askubuntu.com/questions/898449/k...r-updating

If you don't want to submit support requests when you need a reboot, maybe it would be better to use a different OS.  

As far as I can see after I read through the above discussions I found the following:

1. Ubuntu has issues after an update when the reboot is made on the user level.  Something happens that has an effect on the SSH and or Firewall configuration
2. Reboot is probably better on the management console level
3. If you don't have a management console, and don't want to have to submit support requests for reboots, then it may be an idea to use a different OS instead.