Use a Live CD to boot your ESX host and fix the host from a chroot environment.
Boot from the Rescue CD.
Check device names for / and /boot filesystems.
For Example, Internal RAID /boot can be /dev/cciss/c0d0p1 and / can be /dev/cciss/c0d0p7
Run the following command to mount the / filesystem and chroot to it:
mkdir /mnt/root
mount /dev/cciss/c0d0p7 /mnt/root
chroot /mnt/root
Run the following command to mount /boot filesystem to /boot mountpoint:
mount /dev/cciss/c0d0p1 /boot
Ensure the /boot contains the kernel, initrd, grub/ subdir with stage* files, grub.conf and menu.lst , which is a symlink to grub.conf.
You need to replace anything from step 5 that is missing.
Run the following command if any of the stage files are missing:
cp /usr/share/grub/i386-redhat/* /boot/grub/
You can copy all the files from /usr/share/grub/i386-redhat/ to /boot/grub/ .
If grub.conf is missing, you have to create a new one or take a copy from another server.
An example of /boot/grub/grub.conf is:
vmware:configversion 1
# grub.conf generated by anaconda
#
# Note that you do not have to rerun grub after making changes to this file
# NOTICE: You have a /boot partition. This means that
# all kernel and initrd paths are relative to /boot/, eg.
# root (hd0,0)
# kernel /vmlinuz-version ro root=/dev/sdc2
# initrd /initrd-version.img
#boot=/dev/sdc
timeout=10
default=0
title VMware ESX Server
#vmware:autogenerated esx
root (hd0,0)
uppermem 277504
kernel –no-mem-option /vmlinuz-2.4.21-47.0.1.ELvmnix ro root=/dev/cciss/c0d0p7 mem=272M
initrd /initrd-2.4.21-47.0.1.ELvmnix.img
title VMware ESX Server (debug mode)
#vmware:autogenerated esx
root (hd0,0)
uppermem 277504
kernel –no-mem-option /vmlinuz-2.4.21-47.0.1.ELvmnix ro root=/dev/cciss/c0d0p7 mem=272M console=ttyS0,115200 console=tty0 debug
initrd /initrd-2.4.21-47.0.1.ELvmnix.img-dbg
title Service Console only (troubleshooting mode)
#vmware:autogenerated esx
root (hd0,0)
uppermem 277504
kernel –no-mem-option /vmlinuz-2.4.21-47.0.1.ELvmnix ro root=/dev/cciss/c0d0p7 mem=272M tblsht
initrd /initrd-2.4.21-47.0.1.ELvmnix.img-sc
If the server has multiple drives, LUNs, etc., it may be useful to create/edit a /boot/grub/device.map file, with the following content:
(hd0) /dev/cciss/c0d0p1
Where the device name in /dev/ is the boot partition device. Usage of the device.map file significantly speeds up the process, as the GRUB does not have to autodetect devices.
Run the /sbin/grub command if you are using device map file:
/sbin/grub –device-map=/boot/grub/device.map
Run the following command in the GRUB shell:
root (hd0,0)
Run the following command in the GRUB shell:
setup –stage2=stage2 –prefix=/grub (hd0)
Note: This is for setup, where /boot is (hd0) . If this did not work, you can try:
setup (hd0)
Run the quit command to exit the GRUB shell.
Run the following command:
sync
Reboot the server and remove the Rescue CD
Unixskylab 