PXE-KEXEC(8)							     PXE-Kexec							      PXE-KEXEC(8)

NAME

       pxe-kexec - Read PXE configuration file and kexec entries

SYNOPSIS

       pxe-kexec [options] [tftp_server]

DESCRIPTION

   Overview
       pxe-kexec is a tool that fetches PXE configuration from a TFTP server, reads that PXE configuration file, prompts the user for an boot
       entry, downloads the specified kernel and initrd and finally tries to boot the kernel.

       The normal process to boot with kexec(8) is that pxe-kexec loads the kernel and invokes reboot(8). The shutdown script of the Linux
       distribution then executes "kexec -e" at the very end. That is not implemented everywhere.  Therefore, pxe-kexec has a whitelist of Linux
       distributions that support reboot with kexec. If the distribution is not on that whitelist, the program quits with a warning. To bypass
       that warning, please use the "--igore-whitelist" parameter. You can also use the "--force" parameter to execute "kexec -e" to immediately
       boot the selected kernel, without invoking shutdown(8)/reboot(8).

       pxe-kexec meant to be used in an environment where pre-defined PXE configurations exist but the user wants to use kexec(8) instead of
       rebooting.

       Normally, the tftp_server must be specified as first argument. If there's no TFTP server specified, pxe-kexec looks in the DHCP info file
       for the DHCP server and uses this one as TFTP server. This only works when the TFTP server is running on the same machine as the DHCP
       server.

       ==> Please also read the section called "Update Info" <==

   Whitelist
       As mentioned previously, a whitelist of Linux distributions that support kexec-based rebooting is maintained. Currently following
       distributions are on the whitelist:

       o      openSUSE, starting with version 11.0

       o      Ubuntu, starting with version 9.04

       o      Red Hat Enterprise Linux and CentOS, starting with version 5.3

       o      Fedora Linux, starting with version 11

       o      ARCH Linux

       Don't hesitate to send the author an email to add the distribution to the whitelist. Please include the output of "pxe-kexec
       --print-distribution" in that mail.

OPTIONS

       Following options can be specified:

       -h | --help
	      Prints a short help.

       -v | --version
	      Prints the version number to standard output.

       -f | --force
	      Immediately load the kernel without invoking reboot(8). This does not execute shutdown scripts, i.e. does not terminate daemons,
	      network connections etc.

       -L | --load-only
	      When that option is specified, the new kernel is only loaded. No reboot is triggered and "kexec -e" is also not executed.

       -w | --ignore-whitelist
	      Don't check if the detected Linux distribution is on the whitelist of distributions that have kexec(8) in their shutdown script.
	      Please don't use that parameter without letting the author know which distribution you use and how to detect that distribution. Then
	      the distribution can be added to the whitelist and other users profit from that experience.

       -l label | --label label
	      Specifies the label that should be booted. Use that option if you already know which label you want to boot. This option implies
	      "--quiet".

       -i | --interface netif
	      Uses netif instead of the first (non-loopback and up) interface that is found. Example: "eth5".

       -n | --noconfirm
	      Don't ask the user for confirmation before booting an entry. Use that option with care!

       -Y | --dry-run
	      Don't execute call to kexec and don't switch the virtual console before running "kexec -e". Instead, print the information which
	      program would be executed with which arguments to standard error.

       -q | --quiet
	      Don't display the PXE messages that are added in the PXE configuration with the say keyword. Also don't display messages which PXE
	      configuration files the downloader tries to fetch.

       -p | --print-distribution
	      Only prints the detected Linux distribution and exits. For example:

		  Type	      : Ubuntu
		  Name	      : Ubuntu
		  Release     : 9.04
		  Codename    : jaunty
		  Description : Ubuntu 9.04

	      This option is very useful if your distribution is not on the whitelist of Linux distributions that support kexec(8) in the reboot
	      scripts and you want to create a bugreport.

	      This command does not require root privileges.

       -D | --debug
	      Enable debugging output. That's good for finding (and fixing!) bugs.

       -d | --nodelete
	      Keep downloaded files.

       -F | --ftp
	      Always use FTP instead of TFTP. Useful for servers that share TFTP root and FTP root. (Passive) FTP has the advantage that it passes
	      firewalls better than TFTP.

UPDATE INFO

   Updating from 0.1.x to 0.2
       Compared to version 0.1.x, the syntax has changed:

       o      The default label must now be set with the -l label option instead of the 2nd argument. Example:

		% pxe-kexec mydhcp.mydomain.com SLES10-install-auto

	      is now

		% pxe-kexec -l SLES10-install-auto mydhcp.mydomain.com

       o      pxe-kexec now uses the reboot mechanism by default: The kernel is loaded, then the reboot is triggered and the reboot script of the
	      Linux distribution finally boots the kernel. This has the advantage of a clear shutdown.

	      The program keeps a database of Linux distributions that support kexec-based reboot. If the currently active distribution is not on
	      the whitelist, an error is printed. (That whitelist can be ignored with "--ignore-whitelist".)

       o      To use the previous behaviour, i.e. just execute "kexec -e" in pxe-kexec at the end, you can still use the "--force" parameter.
	      Example:

		% pxe-kexec mydhcp.mydomain.com

	      is now

		% pxe-kexec --force mydhcp.mydomain.com

       o      If you want to have the old "dry-run" behaviour back, which in fact only missed the last "kexec -e" step, you can use the option
	      "--load-only".  Example:

		% pxe-kexec --dry-run mydhcp.mydomain.com

	      is now

	       % pxe-kexec --load-only mydhcp.mydomain.com

EXAMPLES

       pxe-kexec mydhcp.mydomain.com
	      Try to fetch the PXE configuration from mydhcp.mydomain.com, display the say messages from that configuration, prompt for an entry,
	      letting the user confirm that entry and finally load that entry via kexec(8) and reboot via reboot(8).

	      This only works if you distribution supports kexec-based rebooting, i.e.	it is in the internal whitelist.

       pxe-kexec -n mydhcp.mydomain.com
	      Same as the previous example, but omit the final confirmation step.

       pxe-kexec -l SLES10-install-auto mydhcp.mydomain.com
	      Same as the first example, but don't prompt the user for the label to boot.  Directly boot the SLES10-install-auto label, but
	      letting the user confirm that he really wants to boot this!

       pxe-kexec -n -l SLES10-install-auto mydhcp.mydomain.com
	      Same as the previous example, but without confirmation.

       pxe-kexec -f mydhcp.mydomain.com
	      Same as the first example, but execute "kexec -e" at the end instead of invoking reboot(8).

       pxe-kexec -l mydhcp.mydomain.com
	      Same as the first example, but don't trigger a reboot. Instead, the kernel is just loaded. If your distribution supports kexec-based
	      rebooting, the kernel will be loaded on next reboot. You can also run "kexec -e" manually at any time.

AUTHOR

       The pxe-kexec program and documentation has been written by Bernhard Walle <bernhard@bwalle.de>.

BUGS

       This program has no bugs. If you find a feature that should be removed, please report to <bernhard@bwalle.de> if you don't want to create
       an account.

SEE ALSO

       kexec(8)

0.2.4								    2011-03-26							      PXE-KEXEC(8)