Never thought about this before, but a quick search gave this:http://www.cgsecurity.org/wiki/OS_Notes
Linux and 48-bit LBA
Linux kernels since at least 2.4.19 have been able to access Large disks (drives over 137 GB using 48-bit LBA); and some earlier kernels, such as Red Hat 7.3's 2.4.18-x, were patched, so check the specific features of your install to know for sure. Linux kernels 2.2.x and older are limited to only 65,535 cylinders.
Beyond that, I didn't find any mention of having to switch on the support. There is however a switch in the kernel config for "Support for Large Block Devices" (for discs > 2 terabytes), which is enabled in the stock 5.8 Standard kernel.