I am using SystemImager to auto-install about 500 different machines, some of them are CentOS; as you can Imagine I want to automate the installation of the bootloader; so I wrote a 2 scripts to accomplish this task. Why two? Because some of the machines are IDE, and some of them are SATA, and I need to be able to use the same disk image on both of the drive types. Here is the first bash script:
if grep -q sda /proc/diskstats then TYPE="sda1" MOUNT1="/dev/sda1 /a/boot" MOUNT2="/dev/sda3 /a" else TYPE="hda1" MOUNT1="/dev/hda1 /a/boot" MOUNT2="/dev/hda3 /a" fi mount $MOUNT2 mount $MOUNT1 MOUNT3="proc /a/proc -t proc -o defaults" mount $MOUNT3 MKSYS="-p /a/sys" MOUNT4="sysfs /a/sys -t sysfs -o defaults" mkdir $MKSYS mount $MOUNT4 MOUNT5="/dev /a/dev -o bind" mount $MOUNT5 echo "mount $MOUNT2" echo "mount $MOUNT1" cp /sbin/grubinstall /a/sbin/grubinstall chmod 755 /a/sbin/grubinstall chmod +x /a/sbin/grubinstall chroot /a /sbin/grubinstall exit 0
What this does is determines whether the drive is SATA or IDE by looking at diskstats, if it is SATA, it mounts /dev/sda1 & /dev/sda3, if it is IDE, it mounts /dev/hda1 & /dev/hda3, it also creates and mounts all of the auxillary filesystems (proc, sys, dev) The next script which I run in the CentOS environment via chroot is:
TYPE= SUBS= if grep -q sda /proc/diskstats then TYPE="sda1" SUBS="s/hda/sda/g" else TYPE="hda1" SUBS="s/sda/hda/g" fi grub-install --no-floppy --recheck /dev/$TYPE sed -i "$SUBS" /boot/grub/menu.lst echo "sed -i $SUBS /boot/grub/menu.lst" sed -i "$SUBS" /etc/fstab echo "sed -i $SUBS /etc/fstab" sed -i "$SUBS" /boot/grub/grub.conf echo "sed -i $SUBS /boot/grub/grub.conf" sed -i "$SUBS" /etc/grub.conf echo "sed -i $SUBS /etc/grub.conf" ls "ls -l /etc/grub.conf /boot/grub/grub.conf /boot/grub/menu.lst" exit 0
By the way /a is the ROOT of the hard drive (freshly imaged) and /a/boot is the boot partition of the hard drive (freshly imaged).
This script again enumerates the type of hard disk attached to the system, installs grub on /dev/hda1 or /dev/sda1, modifies /boot/grub/menu.lst /boot/grub/grub.conf /etc/fstab /etc/grub.conf sda>hda hda>sda and so forth.
Everything actually works fine; grub is installed; the files are all modified appropriately.
The issue comes when the newly imaged system comes up. The first time the system boots up; grub is still configured to boot with root=/dev/sda3; even though NONE of the configuration files mention anything about /dev/sda3. However if I hit 'E' and modify the 'kernel ...' line in the grub editor from the bootloader, and allow it to boot up; the system boots up normally.
The STRANGE part; is that after the first time it boots off of /dev/hda3; grub suddenly starts using that EVERY time the system boots; but I cant figure out why I have to first manually change it; and then reboot before it will work.
Its almost like the CentOS boot process 'fixes' whatever is wrong with grub; the first time it boots after I run my crazy script on it; but I cant figure out what process during the boot is doing it; or what else I need to do to ensure trouble free auto-installation of CentOS, the reason I am asking you all is because that same script appears to work with a few other distributions.
Any advice anyone can give me would be wonderful.
Thanks, -Drew