From f09c2755eee9ece0c0d45ed6e12906635e4aae36 Mon Sep 17 00:00:00 2001 From: Robert Marshall Date: Mon, 16 Mar 2015 16:34:51 -0400 Subject: [PATCH] Update info with grub.cfg netboot selection order (#1148650) Added documentation to the grub info page that specifies the order netboot clients will use to select a grub configuration file. Resolves rhbz#1148650 --- docs/grub.texi | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) diff --git a/docs/grub.texi b/docs/grub.texi index 2fd32608c01..a7155c22ffe 100644 --- a/docs/grub.texi +++ b/docs/grub.texi @@ -2493,6 +2493,48 @@ grub-mknetdir --net-directory=/srv/tftp --subdir=/boot/grub -d /usr/lib/grub/i38 Then follow instructions printed out by grub-mknetdir on configuring your DHCP server. +The grub.cfg file is placed in the same directory as the path output by +grub-mknetdir hereafter referred to as FWPATH. GRUB will search for its +configuration files in order using the following rules where the appended +value corresponds to a value on the client machine. + +@example +@group +@samp{(FWPATH)}/grub.cfg-@samp{(UUID OF NIC)} +@samp{(FWPATH)}/grub.cfg-@samp{(MAC ADDRESS OF NIC)} +@samp{(FWPATH)}/grub.cfg-@samp{(IPv4 OR IPv6 ADDRESS)} +@samp{(FWPATH)}/grub.cfg +@end group +@end example + +The client will only attempt to look up an IPv6 address config once, however, +it will try the IPv4 multiple times. The concrete example below shows what +would happen under the IPv4 case. + +@example +@group +UUID: 7726a678-7fc0-4853-a4f6-c85ac36a120a +MAC: 52:54:00:ec:33:81 +IPV4: 10.0.0.130 (0A000082) +@end group +@end example + +@example +@group +@samp{(FWPATH)}/grub.cfg-7726a678-7fc0-4853-a4f6-c85ac36a120a +@samp{(FWPATH)}/grub.cfg-52-54-00-ec-33-81 +@samp{(FWPATH)}/grub.cfg-0A000082 +@samp{(FWPATH)}/grub.cfg-0A00008 +@samp{(FWPATH)}/grub.cfg-0A0000 +@samp{(FWPATH)}/grub.cfg-0A000 +@samp{(FWPATH)}/grub.cfg-0A00 +@samp{(FWPATH)}/grub.cfg-0A0 +@samp{(FWPATH)}/grub.cfg-0A +@samp{(FWPATH)}/grub.cfg-0 +@samp{(FWPATH)}/grub.cfg +@end group +@end example + After GRUB has started, files on the TFTP server will be accessible via the @samp{(tftp)} device.