adaptec embedded sata, 6.2 install

[Josh Tremor]

Greetings,

Apologies in advance for too much info.

I have a machine by SuperMicro with an adaptec embedded sata that the
manufacturer set to RAID 1 on two 149 GB drives.
I boot the machine, wait for the configuration checker to finish
looking at the array, which says the array is healthy, and then I can
use the 6.2 install discs to set up the partitions and install all of
the packages I choose.  Everything seems fine, but then after
sysinstall finishes and reboots, I get the message 'Operating System
Not Found'.  I can't seem to capture a dmesg output to see what I did
wrong.
The drives are WD caviar SE 1600 but I'm not sure what to do for the
geometry.  What gets reported for a geometry is 310101/16/63 and fdisk
reports 19457 cyls/255 heads/63 sectors.  The system has Embedded
Adaptec SATA BIOS v.5 and I set the partitions as such:

/  20G
swap  30G
/tmp  3G
/home  10G
/opt  40G
/var  10G
/boot 7
/usr  29G


Thanks for any clue.