sudo update-grub

for d in $(sed -ne 's/^.*\(sd.*\)/\1/p' /proc/partitions);do echo -e "$d\t ID: $(sudo hexdump -v -s 0x80 -n 2 -e '2/1 "%x" "\n"' /dev/$d)";done

sda	 ID: 5272
sda1	 ID: b60
sda2	 ID: 55aa
...

sda	 ID: 020
sda1	 ID: 00
sda2	 ID: 00
sda3	 ID: aa75
sda4	 ID: 00
sda5	 ID: 00

                  Boot Info Script 0.60    from 17 May 2011


============================= Boot Info Summary: ===============================

 => Grub2 (v1.99) is installed in the MBR of /dev/sda and looks at sector 1 of 
    the same hard drive for core.img. core.img is at this location and looks 
    for (,msdos1)/boot/grub on this drive.

sda1: __________________________________________________________________________

    File system:       ext4
    Boot sector type:  -
    Boot sector info:  
    Operating System:  Ubuntu 11.04
    Boot files:        /boot/grub/grub.cfg /etc/fstab /boot/grub/core.img

sda2: __________________________________________________________________________

    File system:       Extended Partition
    Boot sector type:  -
    Boot sector info:  

sda5: __________________________________________________________________________

    File system:       swap
    Boot sector type:  -
    Boot sector info:  

sda3: __________________________________________________________________________

    File system:       ext4
    Boot sector type:  Grub Legacy
    Boot sector info:   Grub Legacy (v0.97-71.fc15) is installed in the boot 
                       sector of sda3 and looks at sector 309600154 on boot 
                       drive #1 for the stage2 file.  A stage2 file is at 
                       this location on /dev/sda.  Stage2 looks on partition 
                       #3 for /grub/grub.conf.
    Operating System:  
    Boot files:        /grub/menu.lst /grub/grub.conf

sda4: __________________________________________________________________________

    File system:       LVM2_member
    Boot sector type:  -
    Boot sector info:  

============================ Drive/Partition Info: =============================

Drive: sda _____________________________________________________________________

Disk /dev/sda: 320.1 GB, 320072933376 bytes
255 heads, 63 sectors/track, 38913 cylinders, total 625142448 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes

Partition  Boot  Start Sector    End Sector  # of Sectors  Id System

/dev/sda1    *          2,048   309,569,535   309,567,488  83 Linux
/dev/sda2         619,139,070   625,141,759     6,002,690   5 Extended
/dev/sda5         619,139,072   625,141,759     6,002,688  82 Linux swap / Solaris
/dev/sda3         309,569,536   310,593,535     1,024,000  83 Linux
/dev/sda4         310,593,536   619,137,023   308,543,488  8e Linux LVM


"blkid" output: ________________________________________________________________

Device           UUID                                   TYPE       LABEL

/dev/sda1        ac14d604-5f1d-4029-8d9c-de0c454d0ea5   ext4       
/dev/sda3        407a8f7e-eff8-44ac-8ea8-1bae50bb489c   ext4       
/dev/sda4        fiJ3Nm-Cpt5-DXdY-prbV-T3MD-78Aq-8AWiqh LVM2_member 
/dev/sda5        29df3087-cfe5-4c11-80fe-58855d4715f7   swap       

================================ Mount points: =================================

Device           Mount_Point              Type       Options

/dev/sda1        /                        ext4       (rw,errors=remount-ro,commit=0)


=========================== sda1/boot/grub/grub.cfg: ===========================

--------------------------------------------------------------------------------
#
# 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 video_bochs
  insmod video_cirrus
}

insmod part_msdos
insmod ext2
set root='(/dev/sda,msdos1)'
search --no-floppy --fs-uuid --set=root ac14d604-5f1d-4029-8d9c-de0c454d0ea5
if loadfont /usr/share/grub/unicode.pf2 ; then
  set gfxmode=auto
  load_video
  insmod gfxterm
fi
terminal_output gfxterm
insmod part_msdos
insmod ext2
set root='(/dev/sda,msdos1)'
search --no-floppy --fs-uuid --set=root ac14d604-5f1d-4029-8d9c-de0c454d0ea5
set locale_dir=($root)/boot/grub/locale
set lang=en_IN
insmod gettext
if [ "${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
if background_color 44,0,30; then
  clear
fi
### END /etc/grub.d/05_debian_theme ###

### BEGIN /etc/grub.d/10_linux ###
if [ ${recordfail} != 1 ]; then
  if [ -e ${prefix}/gfxblacklist.txt ]; then
    if hwmatch ${prefix}/gfxblacklist.txt 3; then
      if [ ${match} = 0 ]; then
        set linux_gfx_mode=keep
      else
        set linux_gfx_mode=text
      fi
    else
      set linux_gfx_mode=text
    fi
  else
    set linux_gfx_mode=keep
  fi
else
  set linux_gfx_mode=text
fi
export linux_gfx_mode
if [ "$linux_gfx_mode" != "text" ]; then load_video; fi
menuentry 'Ubuntu, with Linux 2.6.38-8-generic' --class ubuntu --class gnu-linux --class gnu --class os {
	recordfail
	set gfxpayload=$linux_gfx_mode
	insmod part_msdos
	insmod ext2
	set root='(/dev/sda,msdos1)'
	search --no-floppy --fs-uuid --set=root ac14d604-5f1d-4029-8d9c-de0c454d0ea5
	linux	/boot/vmlinuz-2.6.38-8-generic root=UUID=ac14d604-5f1d-4029-8d9c-de0c454d0ea5 ro   quiet splash vt.handoff=7
	initrd	/boot/initrd.img-2.6.38-8-generic
}
menuentry 'Ubuntu, with Linux 2.6.38-8-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os {
	recordfail
	set gfxpayload=$linux_gfx_mode
	insmod part_msdos
	insmod ext2
	set root='(/dev/sda,msdos1)'
	search --no-floppy --fs-uuid --set=root ac14d604-5f1d-4029-8d9c-de0c454d0ea5
	echo	'Loading Linux 2.6.38-8-generic ...'
	linux	/boot/vmlinuz-2.6.38-8-generic root=UUID=ac14d604-5f1d-4029-8d9c-de0c454d0ea5 ro single 
	echo	'Loading initial ramdisk ...'
	initrd	/boot/initrd.img-2.6.38-8-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='(/dev/sda,msdos1)'
	search --no-floppy --fs-uuid --set=root ac14d604-5f1d-4029-8d9c-de0c454d0ea5
	linux16	/boot/memtest86+.bin
}
menuentry "Memory test (memtest86+, serial console 115200)" {
	insmod part_msdos
	insmod ext2
	set root='(/dev/sda,msdos1)'
	search --no-floppy --fs-uuid --set=root ac14d604-5f1d-4029-8d9c-de0c454d0ea5
	linux16	/boot/memtest86+.bin console=ttyS0,115200n8
}
### END /etc/grub.d/20_memtest86+ ###

### BEGIN /etc/grub.d/30_os-prober ###
if [ "x${timeout}" != "x-1" ]; then
  if keystatus; then
    if keystatus --shift; then
      set timeout=-1
    else
      set timeout=0
    fi
  else
    if sleep --interruptible 3 ; then
      set timeout=0
    fi
  fi
fi
### 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 ###
--------------------------------------------------------------------------------

=============================== sda1/etc/fstab: ================================

--------------------------------------------------------------------------------
# /etc/fstab: static file system information.
#
# Use 'blkid -o value -s UUID' to print the universally unique identifier
# for a device; this may be used with UUID= as a more robust way to name
# devices that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
proc            /proc           proc    nodev,noexec,nosuid 0       0
# / was on /dev/sda1 during installation
UUID=ac14d604-5f1d-4029-8d9c-de0c454d0ea5 /               ext4    errors=remount-ro 0       1
# swap was on /dev/sda5 during installation
UUID=29df3087-cfe5-4c11-80fe-58855d4715f7 none            swap    sw              0       0
--------------------------------------------------------------------------------

=================== sda1: Location of files loaded by Grub: ====================

           GiB - GB             File                                 Fragment(s)

   0.045833588 = 0.049213440    boot/grub/core.img                             1
  72.223777771 = 77.549690880   boot/grub/grub.cfg                             1
   2.259880066 = 2.426527744    boot/initrd.img-2.6.38-8-generic               2
   0.044116974 = 0.047370240    boot/vmlinuz-2.6.38-8-generic                  1
   2.259880066 = 2.426527744    initrd.img                                     2
   0.044116974 = 0.047370240    vmlinuz                                        1

============================= sda3/grub/grub.conf: =============================

--------------------------------------------------------------------------------
# grub.conf generated by anaconda
#
# Note that you do not have to rerun grub after making changes to this file
# NOTICE:  You have a /boot partition.  This means that
#          all kernel and initrd paths are relative to /boot/, eg.
#          root (hd0,2)
#          kernel /vmlinuz-version ro root=/dev/mapper/vg_linuxfedora-lv_root
#          initrd /initrd-[generic-]version.img
#boot=/dev/sda3
default=0
timeout=0
splashimage=(hd0,2)/grub/splash.xpm.gz
hiddenmenu
title Fedora (2.6.38.6-26.rc1.fc15.x86_64)
	root (hd0,2)
	kernel /vmlinuz-2.6.38.6-26.rc1.fc15.x86_64 ro root=/dev/mapper/vg_linuxfedora-lv_root rd_LVM_LV=vg_linuxfedora/lv_root rd_LVM_LV=vg_linuxfedora/lv_swap rd_NO_LUKS rd_NO_MD rd_NO_DM LANG=en_US.UTF-8 SYSFONT=latarcyrheb-sun16 KEYTABLE=us rhgb quiet
	initrd /initramfs-2.6.38.6-26.rc1.fc15.x86_64.img
--------------------------------------------------------------------------------

=================== sda3: Location of files loaded by Grub: ====================

           GiB - GB             File                                 Fragment(s)

 147.628855705 = 158.515276800  grub/grub.conf                                 1
 147.628855705 = 158.515276800  grub/menu.lst                                  1
 147.628973007 = 158.515402752  grub/stage2                                    1
 147.645443916 = 158.533088256  initramfs-2.6.38.6-26.rc1.fc15.x86_64.img      2
 147.622540474 = 158.508495872  initrd-plymouth.img                            1
 147.626417160 = 158.512658432  vmlinuz-2.6.38.6-26.rc1.fc15.x86_64            1

========= Devices which don't seem to have a corresponding hard drive: =========

sdb 

=============================== StdErr Messages: ===============================

unlzma: Decoder error