grub.cfg has references to insmod part_msdos when filesystem is ext4

[Trevor]

Binary package hint: grub

10.10 64 bit installed from usb created using 10.04 64 bit & 10.10 final iso (kernel 2.6.35-22)

grub.cfg contains references:

insmod part_msdos
&
set root='(hd0,msdos8)'

even though my partition is ext4. These lines are not present / are different in 10.04

When I updated to kernel 2.6.35-25 via update manager, the same grub.cfg was generated - i.e. no reference to kernel 2.6.35-25, just the 2.6.35-25

grub.cfg contents:

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

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

function recordfail {
  set recordfail=1
  if [ -n "${have_grubenv}" ]; then if [ -z "${boot_once}" ]; then save_env recordfail; fi; fi
}

function load_video {
  insmod vbe
  insmod vga
}

insmod part_msdos
insmod ext2
set root='(hd0,msdos8)'
search --no-floppy --fs-uuid --set 3dd69c3e-d60b-471f-a70a-c885d2f7bdbf
if loadfont /usr/share/grub/unicode.pf2 ; then
  set gfxmode=640x480
  load_video
  insmod gfxterm
fi
terminal_output gfxterm
insmod part_msdos
insmod ext2
set root='(hd0,msdos8)'
search --no-floppy --fs-uuid --set 3dd69c3e-d60b-471f-a70a-c885d2f7bdbf
set locale_dir=($root)/boot/grub/locale
set lang=en
insmod gettext
if [ "${recordfail}" = 1 ]; then
  set timeout=-1
else
  set timeout=10
fi
### END /etc/grub.d/00_header ###

### BEGIN /etc/grub.d/05_debian_theme ###
set menu_color_normal=white/black
set menu_color_highlight=black/light-gray
### END /etc/grub.d/05_debian_theme ###

### BEGIN /etc/grub.d/10_linux ###
menuentry 'Ubuntu, with Linux 2.6.35-22-generic' --class ubuntu --class gnu-linux --class gnu --class os {
    recordfail
    insmod part_msdos
    insmod ext2
    set root='(hd0,msdos8)'
    search --no-floppy --fs-uuid --set 3dd69c3e-d60b-471f-a70a-c885d2f7bdbf
    linux /boot/vmlinuz-2.6.35-22-generic root=UUID=3dd69c3e-d60b-471f-a70a-c885d2f7bdbf ro quiet splash
    initrd /boot/initrd.img-2.6.35-22-generic
}
menuentry 'Ubuntu, with Linux 2.6.35-22-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os {
    recordfail
    insmod part_msdos
    insmod ext2
    set root='(hd0,msdos8)'
    search --no-floppy --fs-uuid --set 3dd69c3e-d60b-471f-a70a-c885d2f7bdbf
    echo 'Loading Linux 2.6.35-22-generic ...'
    linux /boot/vmlinuz-2.6.35-22-generic root=UUID=3dd69c3e-d60b-471f-a70a-c885d2f7bdbf ro single
    echo 'Loading initial ramdisk ...'
    initrd /boot/initrd.img-2.6.35-22-generic
}
### END /etc/grub.d/10_linux ###

### BEGIN /etc/grub.d/20_linux_xen ###
### END /etc/grub.d/20_linux_xen ###

### BEGIN /etc/grub.d/20_memtest86+ ###
menuentry "Memory test (memtest86+)" {
    insmod part_msdos
    insmod ext2
    set root='(hd0,msdos8)'
    search --no-floppy --fs-uuid --set 3dd69c3e-d60b-471f-a70a-c885d2f7bdbf
    linux16 /boot/memtest86+.bin
}
menuentry "Memory test (memtest86+, serial console 115200)" {
    insmod part_msdos
    insmod ext2
    set root='(hd0,msdos8)'
    search --no-floppy --fs-uuid --set 3dd69c3e-d60b-471f-a70a-c885d2f7bdbf
    linux16 /boot/memtest86+.bin console=ttyS0,115200n8
}
### END /etc/grub.d/20_memtest86+ ###

### BEGIN /etc/grub.d/30_os-prober ###
menuentry "Ubuntu, with Linux 2.6.32-25-generic (on /dev/sda1)" {
    insmod part_msdos
    insmod ext2
    set root='(hd0,msdos1)'
    search --no-floppy --fs-uuid --set 7a535784-fb3f-4794-9381-bb05b7d1581b
    linux /boot/vmlinuz-2.6.32-25-generic root=UUID=7a535784-fb3f-4794-9381-bb05b7d1581b ro rootfstype=ext4 acpi_enforce_resources=lax quiet splash
    initrd /boot/initrd.img-2.6.32-25-generic
}
menuentry "Ubuntu, with Linux 2.6.32-25-generic (recovery mode) (on /dev/sda1)" {
    insmod part_msdos
    insmod ext2
    set root='(hd0,msdos1)'
    search --no-floppy --fs-uuid --set 7a535784-fb3f-4794-9381-bb05b7d1581b
    linux /boot/vmlinuz-2.6.32-25-generic root=UUID=7a535784-fb3f-4794-9381-bb05b7d1581b ro single
    initrd /boot/initrd.img-2.6.32-25-generic
}
menuentry "Microsoft Windows XP Professional (on /dev/sda3)" {
    insmod part_msdos
    insmod ntfs
    set root='(hd0,msdos3)'
    search --no-floppy --fs-uuid --set 1ca348fd6588dbd7
    drivemap -s (hd0) ${root}
    chainloader +1
}
### 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 ###

### BEGIN /etc/grub.d/41_custom ###
if [ -f $prefix/custom.cfg ]; then
  source $prefix/custom.cfg;
fi
### END /etc/grub.d/41_custom ###

[Steve Langasek (vorlon)]

This is not a bug. "part_msdos" is the module used to access DOS partition /tables/. The filesystem support is loaded with a separate 'insmod ext2' line (if needed; this may not be needed for ext4).

AIUI, these lines were not present in Ubuntu 10.04 because the syntax of grub.cfg in that release did not require them.