Why does one can't boot from base kernel version during kernel downgrade & Menuentry text in the grub2.cfg for base kernel version changes after executing grub2-mkconfig?

Issue

• In Red Hat Enterprise Linux 7.1 environment, in order to downgrade the kernel version fromlets say 3.10.0-327.10.1.el7.x86_64 to the base kernel version 3.10.0-229.el7.x86_64 , grub2. cfg has to be edited so as to point to the menuentry of the base kernel version.

• To perform the downgrade, following steps are executed:

  • In the updated state, retrieve the menuentry of the base kernel version from the grub2.cfg file. Referred the Documentation
  • The menuentry for the base kernel version obtained from step 1 is menuentry Red Hat Enterprise Linux Server 7.1 (Maipo), with Linux 3.10.0-229.el7.x86_64
  • Set the above menu entry in the /boot/grub/grubenv (GRUB_DEFAULT is pointing to saved) by issuing the grub2-set-default command.
  • Execute the grub2-mkconfig command.

• Observation:

  • After executing grub2-mkconfig, it is observed that menu title for the base kernel version in grub2.cfg changes from menuentry Red Hat Enterprise Linux Server 7.1 (Maipo), with Linux 3.10.0-229.el7.x86_64 to menuentry Red Hat Enterprise Linux Server (3.10.0-229.el7.x86_64) 7.1 (Maipo)
  • Now, when the system is rebooted, the saved_entry has a text menuentry Red Hat Enterprise Linux Server 7.1 (Maipo), with Linux 3.10.0-229.el7.x86_64, which is not present in the grub2.cfg. Hence when the system boots up, it is unable to find the saved_entry and doesn't boot from the base kernel version as a result of the inconsistency in the text in the grub2.cfg and the saved_entry in the grubenv file.

• Is this a bug? What can be the solution?