I am trying to build a minimal linux, for experimenting out with drivers (LLD 3 book refers kernel version 2.6.10). LFS looks out to be a hell of a task...
Yeah, it is. If you just want a minimal linux with a custom kernel, you certainly don't have to build the entire userland too! Pick a goal:
Experiment with driver development.
Build linux from scratch.
Not both, because if what you really want to do is #1, #2 is just an unnecessary waste of time. And not a short length of time, as you are finding out, although that blog is quite short, I suspect you are going to have a lot more problems and questions if you keep going. Think: days. Like, whole days, plural. And a very high probability that sometime during day 2 or 3, you are going to agree with me and shelve LFS rather than wasting more time.
I don't want to mess up my existing system, that why I chose virtualization.
"Messing up your system" is almost certainly not an issue with testing kernel drivers, except in the sense of messing up the running state. I.e., you won't do any harm that isn't fixed by a reboot. By "almost certainly not" I mean if it is a risk, you'll know because of the peculiar nature of whatever you are doing. But you won't by working through LDD 3.
However, it is very easy to mess up the running state enough to require a reboot, which can become a tedious hassle, and does run a small risk of corrupting the filesystem if "reboot" means flicking the switch because the kernel won't come out of panic -- which makes using a VM a good idea. I don't think QEMU is the best choice, though, unless you are trying to simulate foreign hardware. Which you almost certainly don't need/want to do in this case.
So, here's my advice: if you are on an x86 or x86_64 machine, use an x86(_64) VM like virtualbox. Use whatever image you want, and install a custom kernel. Again: you do not need to build the userspace to run a custom kernel. You just need to build and install the kernel into an existing userspace (or OS image). Just the kernel. Nothing but the kernel. That's all. You can do that in < 15 minutes, although it may take hours the first time reading all the configuration stuff.
But: you don't even need a custom kernel to experiment with module building. You just need the source for the kernel used in your image. Although LDD 3 is dated, the 3.x kernel is not so substantially different than the 2.6 kernel. A lot of drivers, etc., in 3.x are completely unchanged from 2.6.
OTOH, having some experience building kernels may provide you with insights vis. kernel programming.