In short - you've got to be very careful what hard drives you install into B&Ws. I knew this, but still had trouble. I'll go into some details of what happened and why to hopefully save others the trouble.
There are two versions of B&W G3, Rev.1 and Rev.2. The main difference is the ATA controller chip. The first one they tried can't handle more than one drive, so in trying to keep up it scrambles the data, corrupting your file system and everything on it. Even though I knew this, I thought mine was a Rev.2 what it was really a Rev.1, so I got bit on the backside. How you can tell is by reading the ATA controller chip, which is located between the fourth PCI slot and the ATA connector. The Rev.1 chips say CMD PCI646U2, whereas the Rev.2 chips say CMD 646U2-402. I think I had read that one can tell just by the serial number on the back of the case, but whatever source I had followed before was incorrect.
Another problem is that my drive was too large. I vaguely remembered a limit of about 190 GB of drive size... but that was for MDD G4s! The B&W needs a drive of 130 GB or less. I don't know how installing another drive controller might help. Hopefully it would avoid these problems entirely.
When I read that B&W "don't support" more drives (rev1) or larger drives, they meant it. This is not "unsupported" in the sense that it will work, but is not recommended. It will not work. The drive setup tools and OS installers will not warn you at all. Within a few hours of trying to set up a 9.2.2 system like this, 27% of the file system was corrupt - including the System Resources file.
Never doing that again!