Greetings to the well of knowledge...
I know this has been discussed ad nauseam, but I don't think I've heard an answer to this one:
Understanding that the storage would need to be reconfigured and that the current backup sets would be lost, can the physical disks in the appliance be replaced to increase capacity? Currently, there are four 1.8 TB drives in the appliance configured as RAID 5. Why can I not replace these with 3TB drives and rebuild the storage and the database? Seems like this should be possible.
No, never seen that as an option or hardware upgrade possibility.
You've got around 5TB useable without dedupe factored in with those drives. The HCL doesn't state they can be replaced.