The first non x86 machine of mine was a 270MHz Ultra SPARC 5, that over the early years was tuned up a little with a 360MHz UltraSparc IIi, some additional RAM (to 256MB) and an Adapted SCSI controller with a U160 IBM disk. As the Adaptect controller has no OpenFirmware ROM I had to keep an IDE drive for booting, and thus just pluged a spare 2.5″ laptop disk over the floppy which just holds the /boot partition. Recently, however I noticed SILO look extraordinarily long to load while the IDE drive made very disgusting clicking sounds. I figured I’d better replace that drive soon before I have a non-booting SPARC and got a 512MB IDE flash module (after all I just need it to hold SILO, the kernel and the initrd. However, to my suprise, freshly formated with a Sun disklabel generated by fdisk the OpenFirmware would just hang during boot, not loading anything of SILO at all. After some back and forth with my T2 sparc64 recovery CD, the old fashioned regular disk and Google not spitting out anything useful for troubleshooting this problem, I just manually edited the disklabel to another CHS geometry than auto-detected and it just worked again. Puh!
For the records, the (Model=TRANSCEND) flash drive fakes to have CHS=993/16/63 and cfdisk happily fills this values into the partition label, however my former disklabel had 255 heads encoded and thus I manually tweaked the flash disks label to 255 heads, likewise: CHS=62/255/63.
Hope that helps others with ancient hardware.