Setting up SSD caching
 

I have a server with CentOS 6.5 installed(accidentally updated, removed the 6.5 kernel and set default boot to the 6.4 kernel 2.6.32-358.el6.x86_64)
It has a 500Gb SATA HDD, and a 128Gb SATA SSD.
I already have the 500Gb HDD setup, with around 40 Gb for /, and the rest for a physical volume part of a volumegroup for KVM(QEMU).
Now, what I want to do is use the 128Gb SSD for a writethrough cache setup.
I just want to use caching for the physical volume that is part of the volumegroup.
What should I do? I absolutely do not want to format the server, under any circumstances.
So how do I setup the SSD caching?

It looks like you need kernel 3.9 or higher as 2.6 did not support these features. Release notes.