Segui este tutorial e consegui resolver o problema.
Instalei o Ubuntu 12.04 LTS alonside com o Windows 8.1 em uma partição de logica separada.
Agora, só posso entrar no Ubuntu. Quando tento logar no Windows pelo menu GRUB, recebo um erro que me leva de volta ao menu GRUB. Aqui está o meu cat /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 "${boot_once}" ]; then save_env recordfail; fi; fi
}
function load_video {
insmod efi_gop
insmod efi_uga
insmod video_bochs
insmod video_cirrus
}
insmod part_gpt
insmod ext2
set root='(hd0,gpt5)'
search --no-floppy --fs-uuid --set=root c6cb0b77-0048-47b5-9b93-6b28c43c4900
if loadfont /usr/share/grub/unicode.pf2 ; then
set gfxmode=auto
load_video
insmod gfxterm
insmod part_gpt
insmod ext2
set root='(hd0,gpt5)'
search --no-floppy --fs-uuid --set=root c6cb0b77-0048-47b5-9b93-6b28c43c4900
set locale_dir=($root)/boot/grub/locale
set lang=en_US
insmod gettext
fi
terminal_output gfxterm
if [ "${recordfail}" = 1 ] ; then
set timeout=-1
else
set timeout=10
fi
### END /etc/grub.d/00_header ###
### BEGIN /etc/grub.d/05_debian_theme ###
set menu_color_normal=white/black
set menu_color_highlight=black/light-gray
if background_color 44,0,30; then
clear
fi
### END /etc/grub.d/05_debian_theme ###
### BEGIN /etc/grub.d/10_linux ###
function gfxmode {
set gfxpayload="${1}"
if [ "${1}" = "keep" ]; then
set vt_handoff=vt.handoff=7
else
set vt_handoff=
fi
}
if [ "${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 3.11.0-26-generic' --class ubuntu --class gnu-linux --class gnu --class os {
recordfail
gfxmode $linux_gfx_mode
insmod gzio
insmod part_gpt
insmod ext2
set root='(hd0,gpt5)'
search --no-floppy --fs-uuid --set=root c6cb0b77-0048-47b5-9b93-6b28c43c4900
linux /boot/vmlinuz-3.11.0-26-generic.efi.signed root=UUID=c6cb0b77-0048-47b5-9b93-6b28c43c4900 ro quiet splash $vt_handoff
initrd /boot/initrd.img-3.11.0-26-generic
}
menuentry 'Ubuntu, with Linux 3.11.0-26-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os {
recordfail
insmod gzio
insmod part_gpt
insmod ext2
set root='(hd0,gpt5)'
search --no-floppy --fs-uuid --set=root c6cb0b77-0048-47b5-9b93-6b28c43c4900
echo 'Loading Linux 3.11.0-26-generic ...'
linux /boot/vmlinuz-3.11.0-26-generic.efi.signed root=UUID=c6cb0b77-0048-47b5-9b93-6b28c43c4900 ro recovery nomodeset
echo 'Loading initial ramdisk ...'
initrd /boot/initrd.img-3.11.0-26-generic
}
submenu "Previous Linux versions" {
menuentry 'Ubuntu, with Linux 3.11.0-15-generic' --class ubuntu --class gnu-linux --class gnu --class os {
recordfail
gfxmode $linux_gfx_mode
insmod gzio
insmod part_gpt
insmod ext2
set root='(hd0,gpt5)'
search --no-floppy --fs-uuid --set=root c6cb0b77-0048-47b5-9b93-6b28c43c4900
linux /boot/vmlinuz-3.11.0-15-generic root=UUID=c6cb0b77-0048-47b5-9b93-6b28c43c4900 ro quiet splash $vt_handoff
initrd /boot/initrd.img-3.11.0-15-generic
}
menuentry 'Ubuntu, with Linux 3.11.0-15-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os {
recordfail
insmod gzio
insmod part_gpt
insmod ext2
set root='(hd0,gpt5)'
search --no-floppy --fs-uuid --set=root c6cb0b77-0048-47b5-9b93-6b28c43c4900
echo 'Loading Linux 3.11.0-15-generic ...'
linux /boot/vmlinuz-3.11.0-15-generic root=UUID=c6cb0b77-0048-47b5-9b93-6b28c43c4900 ro recovery nomodeset
echo 'Loading initial ramdisk ...'
initrd /boot/initrd.img-3.11.0-15-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_gpt
insmod ext2
set root='(hd0,gpt5)'
search --no-floppy --fs-uuid --set=root c6cb0b77-0048-47b5-9b93-6b28c43c4900
linux16 /boot/memtest86+.bin
}
menuentry "Memory test (memtest86+, serial console 115200)" {
insmod part_gpt
insmod ext2
set root='(hd0,gpt5)'
search --no-floppy --fs-uuid --set=root c6cb0b77-0048-47b5-9b93-6b28c43c4900
linux16 /boot/memtest86+.bin console=ttyS0,115200n8
}
### END /etc/grub.d/20_memtest86+ ###
### BEGIN /etc/grub.d/30_os-prober ###
menuentry "Windows 8 (loader) (on /dev/sda4)" --class windows --class os {
insmod part_gpt
insmod ntfs
set root='(hd0,gpt4)'
search --no-floppy --fs-uuid --set=root BC4254984254596A
drivemap -s (hd0) ${root}
chainloader +1
}
set timeout_style=menu
if [ "${timeout}" = 0 ]; then
set timeout=10
fi
### END /etc/grub.d/30_os-prober ###
### BEGIN /etc/grub.d/30_uefi-firmware ###
menuentry 'System setup' {
fwsetup
}
### END /etc/grub.d/30_uefi-firmware ###
### 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 ###
A execução de sudo lsblk -o NAME,FSTYPE,SIZE,MOUNTPOINT,LABEL gera isso:
NAME FSTYPE SIZE MOUNTPOINT LABEL
sda 931.5G
├─sda1 ntfs 1023M Windows RE tools
├─sda2 vfat 360M /boot/efi SYSTEM
├─sda3 128M
├─sda4 ntfs 809.3G OS
├─sda5 ext4 53.5G /
├─sda6 ntfs 9.6G Private
├─sda7 ntfs 47.7G Linux
├─sda8 ntfs 350M
└─sda9 swap 9.6G [SWAP]
sr0 1024M