Host the contents of the Oracle VM Server ISO image file over the network so that you can access the required GRUB2 package files.

Log in to the Oracle VM Manager Web Interface.

Clone the Oracle Linux 6 virtual machine and ensure that it is not attached to a hard disk of 2TiB in size.

Attach the 2TiB hard disk to the cloned virtual machine.

Install the grub2 packages on the 2TiB hard disk that you attached to the cloned virtual machine, for example:

# cd /tmp
# wget --no-proxy /path/grub2-version.rpm
# wget --no-proxy /path/grub2-tools-version.rpm
# mkdir tmp
# cd tmp
# rpm2cpio ../grub2version.rpm | cpio -iumd
# rpm2cpio ../grub2-tools-version.rpm | cpio -iumd
# /usr/sbin/grub2-install -d ./usr/lib/grub/i386-pc/ --force /dev/sdb
  Installing for i386-pc platform.
  ./usr/sbin/grub2-install: warning: this GPT partition label contains no BIOS Boot 
  Partition; embedding won't be possible.
  ./usr/sbin/grub2-install: warning: Embedding is not possible. GRUB can only be 
  installed in this setup by using blocklists. However, blocklists are UNRELIABLE and 
  their use is discouraged.
  Installation finished. No error reported.

Create the /boot/grub2/grub.cfg configuration as follows:

set default="0"
set timeout=5
menuentry 'Linux' {
    insmod part_gpt
    insmod ext2
    set root='hd0,gpt1'
    linux /vmlinuz-version ro root=/dev/mapper/VolGroup-lv_root
    initrd /initramfs-version.img
}

Re-attach the 2TiB hard disk to the virtual machine that you could not boot.