Firewire is a protocol invented by Apple so you’d have to figure that it would work. With firewire, you are supposed to be able to daisy chain up to 127 devices, whether they are hard drives, scanners, video devices, or a mix of these. Well, things are not good in firewire-ville with Leopard. Under Tiger, I have had some problems with an Epson scanner on firewire. In certain flavors of Mac OS X 10.4.x, the Epson scanner would disappear from the firewire chain. Usually, shutting things down for 10-15 minutes and unplugging everything and plugging it back in would reset the firewire bus and everything would be happy.
That was until Leopard. I have simplified my firewire bus by eliminating most devices except for the Epson scanner, a Canopus AVDC video converter and one external firewire drive. I wanted to add a second firewire drive for Time Machine to backup onto. So I connected a known good firewire drive to the chain under Leopard (10.5.1) and immediately got an error message that the disk could not be repaired. “Simple enough,” I thought, “I will just reformat the drive under Leopard and use it for Time Machine.” So I fired up Disk Utility and hit the “Erase” button. Immediately I was greeted by an error message stating “Initialize Failed. Input/Output Error.” Thinking that perhaps the drive may have mysteriously gone bad in the 20 minutes that I hadn’t used it, I tried a second firewire drive. Reread this paragraph to learn what happened with the second drive.
So, now, either I have 2 firewire drives that have failed at the same time, or something was seriously wrong with Leopard. And, just as troubling was with the two “bad” drives on the firewire bus, the original good drive had disappeared. So I shut everything down and put it all back to the way it was. I waited 15 minutes and powered everything back on with the 2 bad drives disconnected. Everything came back the way it should!
So I took the 2 bad drives and connected them to and old PowerBook G4 running trusty, old Tiger (10.4.8) and guess what? The drives immediately mounted on the desktop ready to use! So, something is definitely broken in Leopard with regards to firewire. I initialized the firewire drives in Tiger on the Powerbook and names them something like “Time Machine 1” and “Time Machine 2” and then tried to reconnect them to the desktop tower running Leopard.
This time, the drives popped right up on the desktop! WHADDA??? I went into my Time Machine preferences and targeted the firewire drive for my backup and in less than 2 minutes, Time Machine was happily chugging away backing up my system.
So what did I learn in this several hour experiment (and waste of my time on a holiday weekend)? Absolutely nothing! Leopard broke firewire. And it gives me one more reason to keep an old Tiger machine around just in case I need to fix something or get something done.