From fcd8cdc811153a0e6caf62190a5342300197e676 Mon Sep 17 00:00:00 2001 From: Neil Horman Date: Mon, 28 Jul 2008 11:26:50 +0000 Subject: [PATCH] Resolves: 456572 --- kexec-kdump-howto.txt | 44 +++++++++++++++++++------------------------ kexec-tools.spec | 5 ++++- 2 files changed, 23 insertions(+), 26 deletions(-) diff --git a/kexec-kdump-howto.txt b/kexec-kdump-howto.txt index 418d9d6..0e9acb8 100644 --- a/kexec-kdump-howto.txt +++ b/kexec-kdump-howto.txt @@ -470,30 +470,24 @@ kexec. Note that the kdump kernel should still be able to create a dump, and when the system reboots, video should be restored to normal. -Notes on RHEL5 configuration: - -The RHEL5 kexec-utils package contains two extra configuration files: - -/etc/sysconfig/kdump - This file allows you to specify an alternate kernel to boot in the -event of a panic (other than the kernel running at the moment), and allows you -to override or append options on the kernel command line. It also alows you -to pass extra options to the kexec utility when the kdump service is starting. -See documentation in the template kdump sysconfig file for exact usage - -/etc/kdump.conf - This file allows you to configure how kdump will record your core -file. Unlike the stock version of kdump, the RHEL5 version of kdump attempts -to record your vmcore file from the initramfs, so as to still function -properly in the event that your root file system is corrupted and unmountable. -This file is interrogated on kdump service start and is used to populate the -initramfs for the kdump kernel with the appropriate data and utilities to copy -your core file to the desired location. See documentation in /etc/kdump.conf -for available config directives and targets. Note especially the ifc option. -kdump will attempt to determine which network interface to use when dumping to -a remote server, but due to the possibility of interface renaming, or alternate -module load strategies, the interface name may change in the kdump kernel. -This option is used to override that guess, so that the appropriate interface -will be activated in the kdump kernel. +Notes on resetting video: +Video is a notoriously difficult issue with kexec. Video cards contain ROM code +that controls their initial configuration and setup. This code is nominally +accessed and executed from the Bios, and otherwise not safely executable. Since +the purpose of kexec is to reboot the system without re-executing the Bios, it +is rather difficult if not impossible to reset video cards with kexec. The +result is, that if a system crashes while running in a graphical mode (i.e. +running X), the screen may appear to become 'frozen' while the dump capture is +taking place. A serial console will of course reveal that the system is +operating and capturing a vmcore image, but a casual observer will see the +system as hung until the dump completes and a true reboot is executed. +There are two possiblilties to work around this issue. One is by adding +--reset-vga to the kexec command line options in /etc/sysconfig/kdump. This +tells kdump to write some reasonable default values to the video card register +file, in the hopes of returning it to a text mode such that boot messages are +visible on the screen. It does not work with all video cards however. +Secondly, it may be worth trying to add vga15fb.ko to the extra_modules list in +/etc/kdump.conf. This will attempt to use the video card in framebuffer mode, +which can blank the screen prior to the start of a dump capture. diff --git a/kexec-tools.spec b/kexec-tools.spec index 22ea524..69c2199 100644 --- a/kexec-tools.spec +++ b/kexec-tools.spec @@ -1,6 +1,6 @@ Name: kexec-tools Version: 1.102pre -Release: 13%{?dist} +Release: 14%{?dist} License: GPL Group: Applications/System Summary: The kexec/kdump userspace component. @@ -265,6 +265,9 @@ done %changelog +* Mon Jul 28 2008 Neil Horman - 1.102pre-14 +- Add video reset section to docs (bz 456572) + * Mon Jul 11 2008 Neil Horman - 1.102pre-13 - Fix mkdumprd to support dynamic busybox (bz 443878)