I'm wondering about drawbacks or benefits of creating a chain of two FireWire drives looped back to one computer. I intend to setup two external 1TB drives as either a single 2TB concatenated RAID array or a striped RAID 0 array to be used as a Time Machine backup volume. All ports and cables are FireWire 400.
The setup in question would be:
Setup 1 (loop)
Mac FireWire Port 1<--->External Drive A FireWire Port 1/External Drive A FireWire Port 2<--->External Drive B FireWire Port 1/External Drive B FireWire Port 2<--->Mac FireWire Port 2
vs.
Setup 2 (one long chain)
Mac FireWire Port 1<--->External Drive A FireWire Port 1/External Drive A FireWire Port 2<--->External Drive B FireWire Port 1
vs.
Setup 3 (two short chains)
Mac FireWire Port 1<--->External Drive A FireWire Port 1
Mac FireWire Port 2<--->External Drive B FireWire Port 1
<---> = FireWire 400 cable
According to Apple, (regarding FireWire 800):
In fact, you can even loop your FireWire 800 chain back to your Mac for redundancy while performing live.
However, according to FireWire Depot:
When you are connecting devices to your computer, don't make a second connection between two devices that are already part of the tree. The devices will not work properly because the transmission of the second connection is blocked and forms a loop within the tree arrangement.
Unless I'm not understanding this, these two statements contradict each other. I tend to believe Apple since they are responsible for much of FireWire's development but such a blatant contradiction makes me wonder. Would anyone be kind enough to shed some light on this?
The setup in question would be:
Setup 1 (loop)
Mac FireWire Port 1<--->External Drive A FireWire Port 1/External Drive A FireWire Port 2<--->External Drive B FireWire Port 1/External Drive B FireWire Port 2<--->Mac FireWire Port 2
vs.
Setup 2 (one long chain)
Mac FireWire Port 1<--->External Drive A FireWire Port 1/External Drive A FireWire Port 2<--->External Drive B FireWire Port 1
vs.
Setup 3 (two short chains)
Mac FireWire Port 1<--->External Drive A FireWire Port 1
Mac FireWire Port 2<--->External Drive B FireWire Port 1
<---> = FireWire 400 cable
According to Apple, (regarding FireWire 800):
In fact, you can even loop your FireWire 800 chain back to your Mac for redundancy while performing live.
However, according to FireWire Depot:
When you are connecting devices to your computer, don't make a second connection between two devices that are already part of the tree. The devices will not work properly because the transmission of the second connection is blocked and forms a loop within the tree arrangement.
Unless I'm not understanding this, these two statements contradict each other. I tend to believe Apple since they are responsible for much of FireWire's development but such a blatant contradiction makes me wonder. Would anyone be kind enough to shed some light on this?