[X4U] firewire hub

[Vard Nelson]

I agree with the remarks at the bottom.  I have chained FireWire hard drives 
and optical drives for several years (only up to about three devices in a 
chain, however) with very little in the way of problems.  I have lost 
several FireWire hard drives as either the cases or the drives themselves 
went bad, but the FireWire processing structure seems to have been 
essentially quite stable, which includes reading from and writing to the 
same volume or different volumes on the same chain.  (We routinely process 
input files on the order of 20-100 GB with equivalent output file sizes.)

My software provider has had some problems with very large data sorts, 
however.  He occasionally will sort data volumes on the order of 300 GB, and 
he says that the FireWire boxes that house four drives in an array will 
almost invariably "get lost"  somewhere along the line.  He says if he cuts 
the size of the job down to 30 GB or so he rarely has problems, but 
something is not quite stable enough to get through the "really" large jobs. 
I do not know this for certain, just passing the input along.  Good luck, 
everyone!

Vard Nelson
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>>
>>> And, by the way, I wouldn't put two FireWire hard drives on the same
>>> chain or attach them to a FireWire hub, I would instead purchase a
>>> multi-port FireWire PCI card.
>>
>> I second Randy's recommendation of not sharing FireWire (or  USB) 
>> bandwidth between simultaneously operating high-speed devices, but  want 
>> to add a cautionary note. Multiple ports on a FireWire (or  USB) PCI card 
>> do not guarantee or even imply that each port has  it's own unshared 
>> bandwidth. I would recommend that unless you can  find documentation to 
>> the contrary that you assume that all ports  on a card will share the 
>> same bandwidth.
>
> These are surely puzzling comments for those of us who are using  firewire 
> drives in a chain as no doubt many of used similarly linked  SCSI drives.
>
> Mine sometimes develop a life of their own (much as SCSI drives used  to) 
> and there seems to be no logical way to restore previous order.  So every 
> few months when one or other drives does not mount I spend a  irritating 
> hour or so pulling cable out and replacing them in a  different order only 
> to go through the same procedure a few months  later.
>
> I assumed that as with SCSI this was just part of life and was only  the 
> other day wondering if a firewire hub would solve this  irritation. `Until 
> now I assumed that daisy chaining was normal and  proper practice but if 
> not could someone please give me/us the  lowdown on this as my hard drives 
> are multiplying!