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Updated atMarch 20, 2024   06:18 AM

VM diagnostics

In emergency situations and when there is no connection to the VM over the network, use VNC console or view VM message logs.

The VNC console

VNC Console is a virtual machine diagnostics and management tool that runs in the browser. Use the VNC console if:

  • the virtual machine does not have an external IP address or is not connected to the Internet;
  • recommended VM connection methods (via SSH or RDP) don't work.

Access to the VNC console appears immediately after the virtual machine is started. This allows you to detect failures during the boot of the operating system.

Features of working with the VNC console:

  • you can only use the Latin alphabet to enter text;
  • the clipboard in the VNC console is not available, you cannot copy and paste the text.

Open the console in the VK Cloud personal account or use the address obtained through the OpenStack CLI.

  1. Go to VK Cloud personal account.
  2. Go to Cloud Computing → Virtual machines.
  3. In the list of virtual machines, click on the name of the VM you need.
  4. On the VM page, go to the tab Console.
  5. If the VM is not running, click the start button on the tab.

VNC console control buttons are available in the personal account interface and in a separate window:

  • Send CtrAltDel — the action of the button depends on the VM's operating system (reboot, opening the lock window, etc.).
  • Update Session — use it to reconnect to the VNC console.

VM message logs

OpenStack provides support for a console running through a VM serial port. This allows you to view the boot logs and other diagnostic information, regardless of the state of the operating system and access to the VM over the network.

If the VM was created from a custom image, configure the console. To do this, add the following parameters to GRUB:

console=tty0 console=ttyS0,115200n8

Make sure that OpenStack client is installed and authenticate to the project.

  • Output all log entries:

    openstack console log show <virtual machine ID>
  • Output a limited number of records:

    openstack console log show --lines <number of entries> <virtual machine ID>