[megaimg]

If you have an R5200 O2, that normally means you placed the drive in a second slot and not the first (booting slot).  Not that it matter too much.  I'm a stickler for having the default IDs because when your RTC battery fails...things will still work. If you have special IDs...then you have to struggle to get it booting again (with as little as I use my machines, isn't worth it).

I have a R1200 300mhz with PCI , so only one hard drive that goes in Position 2...

[mamed]

The O2 (or Octane, etc) can use the highest capacity parallel SCSI drives that were ever made, in the 300 to 320 GB range. For higher capacity you would need to use an external storage solution.

Because it’s 32bit I believe it can support up to 2tb filsystems for a single partition

[robespierre]

XFS is a 64-bit file system in all of its implementations. It allows file sizes to 9 exabytes and volumes to 18 exabytes. Volumes can span multiple physical drives.
The parallel SCSI protocol uses 32-bit LBAs, but the largest disks are 320GB, not 2TB.