XServe G5 Cluster, Boot SCSI

[Daniel Hazelbaker]

Is there a way to boot an XServe G5 Cluster-Node by way of SCSI?  I  
have an external SCSI RAID device that I would like to boot the  
machine off of to get the speed benefits of RAID.  Before I go out  
and buy cables and such I'd like to know if it is even possible. I  
have an Adaptec APD-29160 (Mac edition) and ATTO ExpressPCI UL2s  
cards.  I know in the old days with the MESH controllers you could  
boot off of SCSI, but when you are talking a 3rd party HBA is it  
still possible?

The reason I need to do this is I have an XServe G5 Cluster-Node that  
is running mail services.  The machine appears to be suffering from  
hard disk bottle-neck.  The machine handles IMAP for 80 users and  
about 60,000 messages per month, including spamassassin and clamav.   
 From what I can tell by looking at iostat, top and just observing  
the response times; the single hard disk that comes with the cluster  
node simply cannot keep up with that much activity during peak  
hours.  I could try and just have the machine mount a volume on the  
SCSI RAID during/after boot, but I am a little worried about things  
working okay with all these processes (spamassassin, clamav, cyrus,  
etc.) trying to access a volume (by way of symlinks or changing  
default paths) with a volume that may or may not appear in time, etc.

And no, at the moment we do not have enough money to buy a non- 
cluster G5 or other high-cost solution.  And firewire I have found to  
just not be all that stable in a server environment.

Daniel