Originally Posted by jmbach
FWIW I had a 3TB WD NAS drive running in my OLED S3 with a 2TB image on it until I pulled it to put in my Roamio.
Did not modify the 3TB drive in anyway. Because the OLED S3 has a 32bit MFS structure, I could not expand it beyond 2TB. I have been curious if the HD or HD XL could be expanded beyond 2TB as they have a 64bit MFS structure. Would have to use JMFS to do the expansion. If you attempted it with a native 652 image you can only add a 2TB partition to what you currently have and so would not have the full 3TB used. Since a 658 has a 1TB native image, you could use the whole 3TB. In theory it could work.
I remember that a 3TB drive would not work, at all, in Premieres (not for lack of trying) with the TiVo software versions around at the time people were trying 3TB drives. It wasn't about expanding the drive. The 3TB drives just wouldn't boot, even if if all that was done was a clone of a stock drive to a 3TB one.
I later thought of trying a HPA setting to limit the drives to 2TB. But, nobody was willing to try it, and I didn't want to pay the "fresh on market" price for the 3TB drive, just to try it. Later, it would seem it had to be the software, more so than the drive, since 3TB Premieres are now a DIY, for free, option.
The S3/HD software 11.0h added support for larger external WD DVR Expander drives, also increasing the internal size supported, eliminating the 1.26TB limit (that could be worked-around by rearranging/resizing partitions, before 11.0h).