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I did install grub on /dev/sdb. Please find the output.

# grub2-install /dev/sdb
Installing for i386-pc platform.
error: cannot read `/dev/sda': Input/output error.
error: cannot read `/dev/sda': Input/output error.
error: cannot read `/dev/sda': Input/output error.
error: cannot read `/dev/sda': Input/output error.
error: cannot read `/dev/sda': Input/output error.
grub2-install: warning: Couldn't find physical volume `(null)'. Some modules may be missing from core image..
error: cannot read `/dev/sda': Input/output error.
error: cannot read `/dev/sda': Input/output error.
error: cannot read `/dev/sda': Input/output error.
error: cannot read `/dev/sda': Input/output error.
error: cannot read `/dev/sda': Input/output error.
grub2-install: warning: Couldn't find physical volume `(null)'. Some modules may be missing from core image..
Installation finished. No error reported.

Not sure why it gave sda errors though.

And then cross checked with following command again.

  # dd bs=512 count=1 if=/dev/sdb 2>/dev/null| strings
    ZRr=
    `|f
    \|f1
    GRUB
    Geom
    Hard Disk
    Read
     Error

grub.cfg

### BEGIN /etc/grub.d/00_header ###
if [ -f ${config_directory}/grubenv ]; then
  load_env -f ${config_directory}/grubenv
elif [ -s $prefix/grubenv ]; then
  load_env
fi

if [ "${env_block}" ] ; then
  load_env -f "${env_block}"
fi

if [ "${next_entry}" ] ; then
   set default="${next_entry}"
   set next_entry=
   save_env next_entry
   if [ "${env_block}" ] ; then
     save_env -f "${env_block}" next_entry
   fi
   set boot_once=true
else
   set default="${saved_entry}"
fi

if [ x"${feature_menuentry_id}" = xy ]; then
  menuentry_id_option="--id"
else
  menuentry_id_option=""
fi

export menuentry_id_option

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 load_video {
  if [ x$feature_all_video_module = xy ]; then
    insmod all_video
  else
    insmod efi_gop
    insmod efi_uga
    insmod ieee1275_fb
    insmod vbe
    insmod vga
    insmod video_bochs
    insmod video_cirrus
  fi
}

if [ x$feature_default_font_path = xy ] ; then
   font=unicode
else
insmod part_msdos msdos
insmod diskfilter mdraid1x lvm
insmod ext2
set root='lvmid/m7AEp0-79EG-D2Vi-ELzE-BTzh-C8mN-CLxrpz/S0eZEl-PlBX-E1ZL-oCwL-SmUx-4Qe4-Mz9NHX'
if [ x$feature_platform_search_hint = xy ]; then
  search --no-floppy --fs-uuid --set=root --hint='lvmid/m7AEp0-79EG-D2Vi-ELzE-BTzh-C8mN-CLxrpz/S0eZEl-PlBX-E1ZL-oCwL-SmUx-4Qe4-Mz9NHX'  7c2e3a9c-5f5b-47e3-8a0a-d1e66f12747c
else
  search --no-floppy --fs-uuid --set=root 7c2e3a9c-5f5b-47e3-8a0a-d1e66f12747c
fi
    font="/share/grub2/unicode.pf2"
fi

if loadfont $font ; then
  set gfxmode=auto
  load_video
  insmod gfxterm
  set locale_dir=$prefix/locale
  set lang=POSIX
  insmod gettext
fi
terminal_output gfxterm
insmod part_msdos msdos
insmod diskfilter mdraid1x
insmod ext2
set root='mduuid/531cd341e2c7d5a71c542ad04d9ea589'
if [ x$feature_platform_search_hint = xy ]; then
  search --no-floppy --fs-uuid --set=root --hint='mduuid/531cd341e2c7d5a71c542ad04d9ea589'  96c11697-c3b7-4f11-90fc-3aef207db526
else
  search --no-floppy --fs-uuid --set=root 96c11697-c3b7-4f11-90fc-3aef207db526
fi
insmod gfxmenu
loadfont ($root)/grub2/themes/SLE/DejaVuSans-Bold14.pf2
loadfont ($root)/grub2/themes/SLE/DejaVuSans10.pf2
loadfont ($root)/grub2/themes/SLE/DejaVuSans12.pf2
loadfont ($root)/grub2/themes/SLE/ascii.pf2
insmod png
set theme=($root)/grub2/themes/SLE/theme.txt
export theme
if [ x${boot_once} = xtrue ]; then
  set timeout=0
elif [ x$feature_timeout_style = xy ] ; then
  set timeout_style=menu
  set timeout=8
# Fallback normal timeout code in case the timeout_style feature is
# unavailable.
else
  set timeout=8
fi
### END /etc/grub.d/00_header ###

### BEGIN /etc/grub.d/10_linux ###
menuentry 'SLES12'  --class sles12 --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-simple-690785da-f0f0-4250-b693-5a008acbba10' {
        load_video
        set gfxpayload=keep
        insmod gzio
        insmod part_msdos msdos
        insmod diskfilter mdraid1x
        insmod ext2
        set root='mduuid/531cd341e2c7d5a71c542ad04d9ea589'
        if [ x$feature_platform_search_hint = xy ]; then
          search --no-floppy --fs-uuid --set=root --hint='mduuid/531cd341e2c7d5a71c542ad04d9ea589'  96c11697-c3b7-4f11-90fc-3aef207db526
        else
          search --no-floppy --fs-uuid --set=root 96c11697-c3b7-4f11-90fc-3aef207db526
        fi
        echo    'Loading Linux 3.12.28-4-default ...'
        linux   /vmlinuz-3.12.28-4-default root=UUID=690785da-f0f0-4250-b693-5a008acbba10   resume=/dev/md1 splash=silent quiet crashkernel=232M-:116M  showopts
        echo    'Loading initial ramdisk ...'
        initrd  /initrd-3.12.28-4-default
}
submenu 'Advanced options for SLES12' --hotkey=1 $menuentry_id_option 'gnulinux-advanced-690785da-f0f0-4250-b693-5a008acbba10' {
        menuentry 'SLES12, with Linux 3.12.28-4-default' --hotkey=2 --class sles12 --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-3.12.28-4-default-advanced-690785da-f0f0-4250-b693-

5a008acbba10' {
                load_video
                set gfxpayload=keep
                insmod gzio
                insmod part_msdos msdos
                insmod diskfilter mdraid1x
                insmod ext2
                set root='mduuid/531cd341e2c7d5a71c542ad04d9ea589'
                if [ x$feature_platform_search_hint = xy ]; then
                  search --no-floppy --fs-uuid --set=root --hint='mduuid/531cd341e2c7d5a71c542ad04d9ea589'  96c11697-c3b7-4f11-90fc-3aef207db526
                else
                  search --no-floppy --fs-uuid --set=root 96c11697-c3b7-4f11-90fc-3aef207db526
                fi
                echo    'Loading Linux 3.12.28-4-default ...'
                linux   /vmlinuz-3.12.28-4-default root=UUID=690785da-f0f0-4250-b693-5a008acbba10   resume=/dev/md1 splash=silent quiet crashkernel=232M-:116M  showopts
                echo    'Loading initial ramdisk ...'
                initrd  /initrd-3.12.28-4-default
        }
        menuentry 'SLES12, with Linux 3.12.28-4-default (recovery mode)' --hotkey=3 --class sles12 --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-3.12.28-4-default-recovery-

690785da-f0f0-4250-b693-5a008acbba10' {
                load_video
                set gfxpayload=keep
                insmod gzio
                insmod part_msdos msdos
                insmod diskfilter mdraid1x
                insmod ext2
                set root='mduuid/531cd341e2c7d5a71c542ad04d9ea589'
                if [ x$feature_platform_search_hint = xy ]; then
                  search --no-floppy --fs-uuid --set=root --hint='mduuid/531cd341e2c7d5a71c542ad04d9ea589'  96c11697-c3b7-4f11-90fc-3aef207db526
                else
                  search --no-floppy --fs-uuid --set=root 96c11697-c3b7-4f11-90fc-3aef207db526
                fi
                echo    'Loading Linux 3.12.28-4-default ...'
                linux   /vmlinuz-3.12.28-4-default root=UUID=690785da-f0f0-4250-b693-5a008acbba10  showopts apm=off noresume edd=off powersaved=off nohz=off highres=off processor.max_cstate=1 nomodeset 

x11failsafe crashkernel=232M-:116M
                echo    'Loading initial ramdisk ...'
                initrd  /initrd-3.12.28-4-default
        }
}

### 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+ ###
### END /etc/grub.d/20_memtest86+ ###

### 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 ###

### BEGIN /etc/grub.d/41_custom ###
if [ -f  ${config_directory}/custom.cfg ]; then
  source ${config_directory}/custom.cfg
elif [ -z "${config_directory}" -a -f  $prefix/custom.cfg ]; then
  source $prefix/custom.cfg;
fi
### END /etc/grub.d/41_custom ###

### BEGIN /etc/grub.d/80_suse_btrfs_snapshot ###
### END /etc/grub.d/80_suse_btrfs_snapshot ###

### BEGIN /etc/grub.d/90_persistent ###
### END /etc/grub.d/90_persistent ###

DBServer# cat /proc/mdstat 
Personalities : [raid1] md3 : active raid1 sdc1[0] sdd1[1] 976760640 blocks super 1.0 [2/2] [UU] bitmap: 2/8 pages [8KB], 65536KB chunk

md0 : active raid1 sdb1[1] sda10 1051584 blocks super 1.0 [2/1] [_U] bitmap: 1/1 pages [4KB], 65536KB chunk

md2 : active raid1 sdb3[1] sda30 956832576 blocks super 1.0 [2/1] [_U] bitmap: 2/8 pages [8KB], 65536KB chunk

md1 : active raid1 sdb2[1] sda20 18876288 blocks super 1.0 [2/1] [_U]  bitmap: 0/1 pages [0KB], 65536KB chunk unused devices:

if [ x$feature_default_font_path = xy ] ; then
  font=unicode 
else
  insmod part_msdos msdos 
  insmod diskfilter mdraid1x lvm 
  insmod ext2 
  set root='lvmid/m7AEp0-79EG-D2Vi-ELzE-BTzh-C8mN-CLxrpz/S0eZEl-PlBX-E1ZL-oCwL-SmUx-4Qe4-Mz9NHX'
  if [ x$feature_platform_search_hint = xy ]; then 
    search --no-floppy --fs-uuid --set=root --hint='lvmid/m7AEp0-79EG-D2Vi-ELzE-BTzh-C8mN-CLxrpz/S0eZEl-PlBX-E1ZL-oCwL-SmUx-4Qe4-Mz9NHX' 7c2e3a9c-5f5b-47e3-8a0a-d1e66f12747c 
  else 
    search --no-floppy --fs-uuid --set=root 7c2e3a9c-5f5b-47e3-8a0a-d1e66f12747c 
  fi 
  font="/share/grub2/unicode.pf2" 
fi
 
if loadfont $font ; then 
  set gfxmode=auto 
  load_video 
  insmod gfxterm
  set locale_dir=$prefix/locale 
  set lang=POSIX 
  insmod gettext 
fi
terminal_output gfxterm 
insmod part_msdos msdos 
insmod diskfilter mdraid1x 
insmod ext2 
set root='mduuid/531cd341e2c7d5a71c542ad04d9ea589' 
if [ x$feature_platform_search_hint = xy ]; then 
  search --no-floppy --fs-uuid --set=root --hint='mduuid/531cd341e2c7d5a71c542ad04d9ea589' 96c11697-c3b7-4f11-90fc-3aef207db526 
else 
  search --no-floppy --fs-uuid --set=root 96c11697-c3b7-4f11-90fc-3aef207db526 
fi
 
Quote: The procedure to follow should go like this,

Do I have to do something extra to take care of it or the command sfdisk -d /dev/sdb | sfdisk /dev/sda , should take care of LVM as well.

DBServer# cat /proc/mdstat 
Personalities : [raid1]  

md3 : active raid1 sdc1[0] sdd1[1] 976760640 blocks super 1.0 [2/2] [UU] bitmap: 2/8 pages [8KB], 65536KB chunk

md0 : active raid1 sdb1[1] sda10 1051584 blocks super 1.0 [2/1] [_U] bitmap: 1/1 pages [4KB], 65536KB chunk

md2 : active raid1 sdb3[1] sda30 956832576 blocks super 1.0 [2/1] [_U] bitmap: 2/8 pages [8KB], 65536KB chunk

md1 : active raid1 sdb2[1] sda20 18876288 blocks super 1.0 [2/1] [_U]  bitmap: 0/1 pages [0KB], 65536KB chunk  

unused devices:

if [ x$feature_default_font_path = xy ] ; then
  font=unicode 
else
  insmod part_msdos msdos 
  insmod diskfilter mdraid1x lvm 
  insmod ext2 
  set root='lvmid/m7AEp0-79EG-D2Vi-ELzE-BTzh-C8mN-CLxrpz/S0eZEl-PlBX-E1ZL-oCwL-SmUx-4Qe4-Mz9NHX'
  if [ x$feature_platform_search_hint = xy ]; then 
    search --no-floppy --fs-uuid --set=root --hint='lvmid/m7AEp0-79EG-D2Vi-ELzE-BTzh-C8mN-CLxrpz/S0eZEl-PlBX-E1ZL-oCwL-SmUx-4Qe4-Mz9NHX' 7c2e3a9c-5f5b-47e3-8a0a-d1e66f12747c 
  else 
    search --no-floppy --fs-uuid --set=root 7c2e3a9c-5f5b-47e3-8a0a-d1e66f12747c 
  fi 
  font="/share/grub2/unicode.pf2" 
fi
 
if loadfont $font ; then 
  set gfxmode=auto 
  load_video 
  insmod gfxterm
  set locale_dir=$prefix/locale 
  set lang=POSIX 
  insmod gettext 
fi
terminal_output gfxterm 
insmod part_msdos msdos 
insmod diskfilter mdraid1x 
insmod ext2 
set root='mduuid/531cd341e2c7d5a71c542ad04d9ea589' 
if [ x$feature_platform_search_hint = xy ]; then 
  search --no-floppy --fs-uuid --set=root --hint='mduuid/531cd341e2c7d5a71c542ad04d9ea589' 96c11697-c3b7-4f11-90fc-3aef207db526 
else 
  search --no-floppy --fs-uuid --set=root 96c11697-c3b7-4f11-90fc-3aef207db526 
fi

Quote: The procedure to follow should go like this,

Do I have to do something extra to take care of it or the command sfdisk -d /dev/sdb | sfdisk /dev/sda , should take care of LVM as well.