[X-Newbies] Sharing External HD

[Michael Winter]

On Jul 12, 2005, at 10:00 AM, Morland, Chris wrote:

>
> Have a question about external HD: Can you share an external HD  
> with two computers via firewire ports? Just got a new G5 and a G- 
> Raid external HD it has two 400 and one 800 firewire ports; Can i  
> run the old G4 and the new G5 off the G-Raid at the same time?  
> Thank in advance. - chris

If you're asking can you just plug two Macs into the same external FW  
drive and have it work, the answer is probably -but its a dangerous  
thing to do. At least I wouldn't do it.

 From a technical standpoint, FW is a peer-to-peer protocol, so all  
devices are capable of independent communications and you should be  
able to just plug 'n play. There's is no master-slave relationship  
where one computer "owns" all the devices connected to the bus.

The danger is that since neither computer "owns" the drive, both are  
able to make changes to the drive independent of the other -that can  
be bad. You can imagine all kinds of scenarios where one computer  
alters the content of a file "behind the back" of the other with loss  
of data and mayhem ensuing. The worst case would be both computers  
caching parts of the directory structure and then relying on or  
writing out erroneous or outdated information. I don't know how  
likely that is to happen, I've never wanted to find out.

IIRC different Macs and OS versions handled the situation in  
different ways. If you really want to do it, one way  is to use  
Firewire networking and have one computer "own" the drive and share  
it with the other (I've never actually tried it this way). But  
depending on the computers involved this may be better accomplished  
using ethernet networking (which I have done).

-Mike