3.3.8. Cache Volumes
As of the Red Hat Enterprise Linux 6.7 release, LVM supports the use of fast block devices (such as SSD drives) as write-back or write-though caches for larger slower block devices. Users can create cache logical volumes to improve the performance of their existing logical volumes or create new cache logical volumes composed of a small and fast device coupled with a large and slow device.
For information on creating LVM cache volumes, see Section 5.4.7, “Creating LVM Cache Logical Volumes”.