# Tested on RHEL 5 & 6
# In many cases, the GRUB boot loader can mistakenly be deleted, corrupted or replaced.
# We can manually reinstall GRUB on the master boot record, using either "grub-install"
# or the "grub" prompt.
# Ensure the device.map file located in the /boot/grub directory lists all boot devices
# in the same order detected by system ROM.
# grub-install -----------------------------------------------------------------------------
cat device.map
# this device map was generated by anaconda
(hd0) /dev/cciss/c0d0
# Use the 'grub-install' command pointing to the root device.
grub-install /dev/cciss/c0d0
# --- OR ---
# "grub" utility ---------------------------------------------------------------------------
# Manually set up the MBR and /boot partition from the grub prompt. (hd0) and (hd0,0) should
# coincide with the results from the "find" command. It may be that "find" command will
# fail showing an error message; if that's the case we can continue with the procedure as
# "find" step is not mandatory
grub
grub> find /boot/grub/stage1
grub> root (hd0,0)
grub> setup (hd0)
# ------------------------------------------------------------------------------------------
# If a crash occurred on the server and GRUB boot loader was lost, this may be recovered by
# booting from a rescue CD.
# After the command prompt is displayed, change the root directory to the OS installation
# by typing this command:
chroot </mnt/sysimage>
# Review the /boot/grub/grub.conf file, as additional entries may be needed for GRUB to control
# additional operating systems.
Article Number: 60
Posted: Sun, May 27, 2018 8:36 PM
Last Updated: Sun, May 27, 2018 8:36 PM
Online URL: http://kb.ictbanking.net/article.php?id=60