This drive will be booting Debian so my question is not totally off-topic. Some older P.C. BIOS programs will not boot any drive over 32GB. Can you get a larger drive, partition it with a 32 GB boot partition and expect it to work that way with the remainder of the drive available for more space such as /home?
This sounds like and probably is a stupid question since I presently do this very thing but the boot drive is /dev/sda1 and the big drive is /dev/sdb1 which has about 300 GB on it and runs off the secondary slot on the same controller with no known issues. Maybe a better form of this question is- Are there any unexpected gotchas likely in using SDA1 for the boot drive and SDA2-x for the rest? It will probably be SDA2 for most of the rest with SDA3 being extended and SDA5 swap. My 300 GB drive still works but it is around 8 years old and is a spinning electro mechanical type and it will fail some day about a millisecond after it was working perfectly.