Network booting at Bytemark

You can use our console in order to reboot your machine and access its serial line. This is normally used to fix minor network or firewall errors when your box would otherwise be inaccessible.

However the serial line can also be used to change your system’s boot process in an emergency, or when you want to reinstall the operating system.

Virtual machines do not feature a network boot environment, but you can boot them into a rescue mode instead.

How it works

Every server on our network is set up to boot over the network first before it tries the hard drive. After you have issued a power cycle from the console you should see the following on the serial line within 60 seconds:

##########     BYTEMARK HOSTING  ::   NETWORK BOOT MENU      ##########
#             ------------------------------------------              #
#  Our network boot environment allows you access to your dedicated   #
#  server no matter what state it may be in. . .                      #
#                                                                     #
#  If you know the name of the system you wish to boot, simply type   #
#  it at the prompt. If you wish to boot from your local disk, press  #
#  <RETURN> or wait for the bootloader to time out.  (10 seconds)     #
#                                                                     #
#  For more help you may press:                                       #
#                                                                     #
#     * Ctrl+F 1   -->   Introduction            (this page!)         #
#     * Ctrl+F 2   -->   Rescue Options                               #
#     * Ctrl+F 3   -->   Miscellaneous Options                        #
#                                                                     #
#   ("Ctrl+F 1" means that you should press 'f' whilst holding down)  #
#   (   control, then release both keys and press the digit '1'.   )  #
#######################################################################
 <Ctrl+F 1>: Intro  <Ctrl+F 2>: Rescue Options  <Ctrl+F 3>: Misc Opts.
    For more help please see :  http://www.bytemark.co.uk/dhshell

boot:

This indicates that the system has started its boot process over the network. If you leave the prompt for 10 seconds or type “local” and press enter, it will then boot off its hard drives as usual.

The screen will prompt you to press Ctrl+F then a digit for further instructions on rescue and reinstall options.

The network boot environment

This is probably the most important option to be familiar with, as it allows you to get your host out of a bad kernel upgrade, firewall rule, or forgotten root password.

You can start the netboot environment by typing netboot-amd64 (if you have a very old server you may need to type netboot-x86).

You will see the following:

boot: netboot-amd64
Loading pxelinux.misc/vmlinuz-amd64-steve...............................
Loading pxelinux.misc/linstub-amd64-steve.img.gz................................................................................................................................................................................................
Ready.
Linux version 2.6.19.4 (root@robin) (gcc version 4.1.2 20061115 (prerelease) (Debian 4.1.1-21)) #3 SMP Thu Mar 1 18:46:29 GMT 2007
...

and so on until the boot message is displayed:

= = = = = = = =          Bytemark netboot image          = = = = = = = =

  This is a network boot environment for you to rescue or reimage your
  server.  Documentation is available at www.bytemark.co.uk/booting  

  Quick help:
   * You can mount all your drives on /target with 'mountall'.

   * You can start reinstalling with 'InstallMeADedicatedServer' though
     we'd recommend looking at www.bytemark.co.uk/reimaging first.       

  Please see http://www.bytemark.co.uk/support/ if you need to contact
  Bytemark for any reason - be careful what you do in this shell!

                           Press ENTER to start.

= = = = = = = =         http://www.bytemark.co.uk        = = = = = = = =

If you’re not sure what to do next we’d recommend looking at how to rescue your server or how to reinstall for further instructions.