Provided by: pxe-kexec_0.2.4-3build1_amd64 
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:
• openSUSE, starting with version 11.0
• Ubuntu, starting with version 9.04
• Red Hat Enterprise Linux and CentOS, starting with version 5.3
• Fedora Linux, starting with version 11
• 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:
• 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
• 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".)
• 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
• 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)