I've just acquired a Sun Ultra 24. Decent spec for its era, so still some life in it I think.
It has 4 3.5" hard-drive caddys (I believe part number 330-2238 540-3024). They have plastic rails to screw to a 3.5" drive and a lever mechanism on the front locking them into place; the drives dock against a back panel with SATA plugs protruding from it.
I'd quite like to put a couple of 2.5" SSDs in the box, but it's not obvious how to use them with this caddy system. I've seen 3.5"/2.5" mount adapters, but I assume they expect cables to run to the drive, and it's not obvious they'd be compatible with the fixed-position SATA back panel the caddys hold the drives against: if the drive's SATA ports didn't end up in exactly the right position they wouldn't work. If 3.5" SSDs existed, that'd be a simple solution, but they don't seem to be available these days.
Did Sun ever produce a 2.5"-compatible caddy? Any other solutions to this? Do drive mount bracket adapters actually work better than I think?