4.3.6. VPS won't boot after reboot

After updating the operating system kernel on the VPS and performing a reboot, the server may not boot. At the same time, in the control panel on our website, the VPS status changes to "Switchedoff" a few seconds after switching on.

If you manage to connect to the server using VNC, then, for example, the following error may be displayed there:

To fix the situation, try loading the previous version of the kernel:

  1. Turn on access by VNC and prepare everything for a quick connection (it is advisable to save the connection settings in the VNC client so that you can connect to the server without opening additional windows and entering any parameters).
  2. In our control panel under "VPS" press the button "Launch" to start the server and immediately try to connect via VNC... The first attempts may end in failure, if the server does not have time to start yet — close the window with the message about the failed connection and immediately try again.
  3. If you can connect before the GRUB boot loader starts loading the operating system, you will see the GRUB menu. Press the down or up arrow on the keyboard to stop automatic counting. Now you can select any previous kernel version and try loading it.

If the system boots successfully, edit the GRUB configuration so that it automatically loads the correct kernel version:

  • For GRUB version 0.97: in file /boot/grub/menu.lst you need to change the parameter default, which contains the ordinal number of the menu bar (numbering from zero).
  • For GRUB 2: change the parameter GRUB_DEFAULT in file /etc/default/grub and run update-grub.

In the same files, you can change the parameter timeout (GRUB_TIMEOUT for GRUB 2), which is responsible for the duration of the menu display.