User manual

Etherboot User Manual

/etc/dhcpd.conf? If you are booting lots of clients, is inetd shutting down tftpd for being spawned

too often? If so, you need to get a better inetd or a a dedicated tftpd that runs as an independent

daemon.

• Etherboot loads ﬁle but hangs halfway through the transfer. We have one report that this happens if

the Fast A20 Gate option is selected in the BIOS setup. The A20 issue is explained here

(http://www.win.tue.nl/~aeb/linux/kbd/A20.html). In effect this causes the loaded kernel to overwrite

Etherboot and kill it. Try deselecting the option. You don’t need it for Linux anyway.

• Etherboot loads ﬁle via tftp but Linux fails to mount the root ﬁlesystem, either on an initrd or on

NFSroot. This is a large category. Here are some suggestions:

• You do not have a private copy of the /, /etc, /var, ... directories

• Your /dev directory is missing entries for /dev/zero and/or /dev/null or is sharing device entries

from a server that uses different major and minor numbers (i.e. a server that is not running Linux).

• Your /lib directory is missing libraries (most notably libc* and/or libm*) or does not have the

loader ﬁles ld*.so*

• You neglected to run ldconﬁg to update /etc/ldconﬁg.cache or you do not have a conﬁguration ﬁle

for ldconﬁg.

• Your /etc/inittab and/or /etc/rc.d/* ﬁles have not been customised for the clients. For example if you

set the wrong IP address in your client’s init ﬁles you could interfere with the server.

• Your kernel is missing some crucial compile-time feature (such as NFS ﬁlesystem support, booting

from the net, transname (optional), ELF ﬁle support, networking support_.

• Missing init executable (in one of the directories known by the kernel: /etc, /sbin, ?). Remember

/sbin/init must be a real ﬁle, not a symlink.

• Missing /etc/inittab

• Missing /dev/tty?

• Missing /bin/sh

• System programs that insist on creating/writing to ﬁles outside of /var (mount and /etc/mtab* is the

canonical example)

The essence is that you must provide whatever is needed in the root ﬁlesystem that your kernel needs

to boot.

9. Frequently Answered Questions

Please check this section if you have a problem before asking on the mailing lists.

9.1. Building Etherboot

1. What do I need to build Etherboot?