Bug#565706: grub2 enters rescue mode with "fd0 cannot get C/H/S values"

[Tom Wright]

Package: grub-pc
Version: 1.98~20100128-1.2
Severity: normal

I am seeing the same problem: grub reports this on startup and then gets no further:

error: fd0 cannot get C/H/S values.
entering rescue mode

My system has three RAID1 md partitions across sda and sdb, containing swap, / and /boot and it has another disk (sdc).  With these plugged in, it all works fine, but once I plug a USB drive in as well, the system won't start.  I can get it to start by removing the USB drive and resetting it (ctrl-alt-del or power-cycle).  This is not ideal though, as it's a hidden-away server which always has a USB disk plugged into it for backup purposes, so I cannot reboot it remotely because it won't start up again.

-- Package-specific info:

*********************** BEGIN /proc/mounts
/dev/disk/by-uuid/b8ea7ba8-1e96-4e1c-8993-6a3118767dd5 / ext4 rw,relatime,errors=remount-ro,barrier=1,data=ordered 0 0
/dev/md2 /boot ext3 rw,relatime,errors=continue,data=ordered 0 0
/dev/sdc1 /mythrecordings ext4 rw,relatime,barrier=1,data=ordered 0 0
*********************** END /proc/mounts

*********************** BEGIN /boot/grub/device.map
(hd0)	/dev/sda
(hd1)	/dev/sdb
(hd2)	/dev/sdc
*********************** END /boot/grub/device.map

*********************** BEGIN /boot/grub/grub.cfg
#
# DO NOT EDIT THIS FILE
#
# It is automatically generated by /usr/sbin/grub-mkconfig using templates
# from /etc/grub.d and settings from /etc/default/grub
#

### BEGIN /etc/grub.d/00_header ###
if [ -s $prefix/grubenv ]; then
  load_env
fi
set default="0"
if [ ${prev_saved_entry} ]; then
  set saved_entry=${prev_saved_entry}
  save_env saved_entry
  set prev_saved_entry=
  save_env prev_saved_entry
  set boot_once=true
fi

function savedefault {
  if [ -z ${boot_once} ]; then
    saved_entry=${chosen}
    save_env saved_entry
  fi
}
insmod raid
insmod mdraid
insmod ext2
set root=(md1)
search --no-floppy --fs-uuid --set b8ea7ba8-1e96-4e1c-8993-6a3118767dd5
if loadfont /usr/share/grub/unicode.pf2 ; then
  set gfxmode=640x480
  insmod gfxterm
  insmod vbe
  if terminal_output gfxterm ; then true ; else
    # For backward compatibility with versions of terminal.mod that don't
    # understand terminal_output
    terminal gfxterm
  fi
fi
insmod raid
insmod mdraid
insmod ext2
set root=(md2)
search --no-floppy --fs-uuid --set 7585406e-ce84-4bd5-afb6-e198efa46a94
set locale_dir=($root)/grub/locale
set lang=en
insmod gettext
set timeout=5
### END /etc/grub.d/00_header ###

### BEGIN /etc/grub.d/05_debian_theme ###
set menu_color_normal=cyan/blue
set menu_color_highlight=white/blue
### END /etc/grub.d/05_debian_theme ###

### BEGIN /etc/grub.d/10_linux ###
menuentry "Debian GNU/Linux, with Linux 2.6.32-trunk-amd64" {
	insmod raid
	insmod mdraid
	insmod ext2
	set root=(md2)
	search --no-floppy --fs-uuid --set 7585406e-ce84-4bd5-afb6-e198efa46a94
	echo	Loading Linux 2.6.32-trunk-amd64 ...
	linux	/vmlinuz-2.6.32-trunk-amd64 root=UUID=b8ea7ba8-1e96-4e1c-8993-6a3118767dd5 ro  quiet
	echo	Loading initial ramdisk ...
	initrd	/initrd.img-2.6.32-trunk-amd64
}
menuentry "Debian GNU/Linux, with Linux 2.6.32-trunk-amd64 (recovery mode)" {
	insmod raid
	insmod mdraid
	insmod ext2
	set root=(md2)
	search --no-floppy --fs-uuid --set 7585406e-ce84-4bd5-afb6-e198efa46a94
	echo	Loading Linux 2.6.32-trunk-amd64 ...
	linux	/vmlinuz-2.6.32-trunk-amd64 root=UUID=b8ea7ba8-1e96-4e1c-8993-6a3118767dd5 ro single 
	echo	Loading initial ramdisk ...
	initrd	/initrd.img-2.6.32-trunk-amd64
}
### END /etc/grub.d/10_linux ###

### BEGIN /etc/grub.d/30_os-prober ###
### END /etc/grub.d/30_os-prober ###

### BEGIN /etc/grub.d/40_custom ###
# This file provides an easy way to add custom menu entries.  Simply type the
# menu entries you want to add after this comment.  Be careful not to change
# the 'exec tail' line above.
### END /etc/grub.d/40_custom ###
*********************** END /boot/grub/grub.cfg

-- System Information:
Debian Release: squeeze/sid
  APT prefers testing
  APT policy: (700, 'testing'), (600, 'unstable')
Architecture: amd64 (x86_64)

Kernel: Linux 2.6.32-trunk-amd64 (SMP w/2 CPU cores)
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

Versions of packages grub-pc depends on:
ii  debconf [debconf-2.0]  1.5.28            Debian configuration management sy
ii  grub-common            1.98~20100128-1.2 GRand Unified Bootloader, version 
ii  libc6                  2.10.2-6          Embedded GNU C Library: Shared lib
ii  ucf                    3.0025            Update Configuration File: preserv

grub-pc recommends no packages.

Versions of packages grub-pc suggests:
pn  desktop-base                  <none>     (no description available)

-- debconf information:
  grub-pc/kopt_extracted: false
  grub2/kfreebsd_cmdline:
* grub-pc/install_devices: /dev/sda, /dev/sdb
  grub-pc/postrm_purge_boot_grub: false
* grub2/linux_cmdline:
  grub2/kfreebsd_cmdline_default: quiet
* grub2/linux_cmdline_default: quiet
  grub-pc/chainload_from_menu.lst: true