Do I need to back up my SCSI media or will it be recognized in OSX? I have a MedeaRT with an ATTO UL2S card, am I going to need to download new drivers for the card? When I upgrade to OSX will all the files on my desktop still be available or will it reformatte or something crazy like that? Any other advice would be appreciated.
[matt short]"Do I need to back up my SCSI media or will it be recognized in OSX?"
It depends. If your drives are striped or initialized by anything else than Apples own disk tool you probably need to reformat them under OSX. If they are "standard" HFS+ volumes with no partitioning or striping they should work fine.
[matt short]"I have a MedeaRT with an ATTO UL2S card, am I going to need to download new drivers for the card?"
You definitely should look at ATTOs site for drivers for the card that support the OS you are planning to install. And you either should contact Medea or search the archive here about the Medea stuff, I think I can remember some Medea/OSX problems.
Generally I would suggest keeping your OS9 system folder as it is right now and either install OSX on a FireWire drive or the internal boot drive additionally to your OS9 installation. Install all the software you need under OSX, but leave your array untouched unless you know that everything else is working nicely under OSX: Do some digitizing at a low res on your internal drive to see if Media 100 works as expected. If everything is fine and you have some time without deadlines bring your drives to OSX.