For those of you who are interested, a 1TB XL (748) can be expanded to 3TB. Ggieseke discovered that a Premiere XL can boot from a 3TB drive and that the important thing is that the image you need to work from is one of the later iterations of the OS. I have tried booting with older images but they bootloop. So if you have the original image backed up somewhere, you will need an update to it. Also you will need a copy of JMFS. First copy the updated OS image to a 3TB drive. I used DvrBARS to do a modified backup and a quick restore. However, I believe using a variation of dd will work as well (ie using the copy selection in JMFS). Once that is done, just use JMFS to expand and supersize the image. Here is a picture of my XL with a 3TB drive. I have tried this with the 2TB XL4 (758) image but JMFS fails on expansion. So currently only a 1TB XL (748) can be expanded to the full 3TB drive. For those of you who are adventurous, after copying the 1TB image to the 3TB drive, you can 4k align it manually and then expand and supersize it. Before someone asks, I don't think a Series 3 1TB HD can be expanded this way as JamieP pointed out in another thread, the kernel of Series 3 TiVo's does not appear to be compiled with large disk support. If someone wants to attempt this and report back on their findings then we would know for sure. Just make sure you use 11.0m when you do this.