I have an Intel i5 laptop with 150Gb space and partitioned into 3 parts. Ubuntu 14.10 LTS 64-bit and Mint 17 Cinnamon 64-bit installed in 2 separate partitions. The GRUB 2 bootloader works fine.
Then I installed CentOS 6 64-bit into the third separate partition by using an USB boot drive containing CentOS 6 only. After successful installation the machine was reboot and I can only found the CentOS 6 in the GRUB bootloader. Both Ubuntu and Mint could not be loaded from the bootloader. I know that I have probably replaced the GRUB2 with GRUB.
I have reinstalled the GRUB using the CentOS 6 USB boot drive following the command of the CentOS wiki http://wiki.centos.org/TipsAndTricks/ReinstallGRUB. The rescue mode was chosen after the USB boot. I have run the command:
# chroot /mnt/sysimage
But I could not run the following scripts:
# grub-install /dev/sda # grub-install /dev/sda2
Then I reboot the machine and only I found GRUB2 reappeared in the boot screen. However this time the CentOS 6 was gone.
Is there any way I could be able to choose all the 3 linux distros in the same boot screen? I am a newbie to linux and therefore I would like to know the reason of the above happening?