CentOS AltRoot

On a whim, I just tried a proof of concept with CentOS on the machine I just finished loading. Specifically, I created a couple of additional logical volumes, "altroot" and "altswap" and installed a second copy of CentOS in the free space in the shared root volume group.

I did have to get a bit creative with grub. When I installed the second instance of CentOS, Anaconda took over grub, thus requiring me to go in and modify the grub.conf file by hand. The original grub.conf file had been saved as grub.conf.rpmsave. So, I just copied the lines I wanted out of the grub.conf.rpmsave in to grub.conf. There was a bit of confusion on the kernel line for the new / second install with where the ram disk was to be mounted. Namely, the rd_LVM_LV tried to refer to the real swap, not altswap. After tweaking the grub.conf file, I was able to easily and happily reboot between the two CentOS installs on the same system.

I have no idea where this proof of concept will be used, but hey, what that's half the fun of it. :-D