To clarify my question, I have 4 PCs at home (2 nForce2 boards, 1 nForce4, 1 Asus P5B-E). All of them are able to boot Unraid using a Sandisk Micro Cruzer 1GB USB drive. The USB drive is formated using HP utility in FAT, and I executed syslinux command on it. I also make sure the volume name is 'UNRAID'.
One of the nForce2 motherboards is currently unused, so I am planning to make it into an Unraid server. However, something is wrong during the booting process, the folder /boot/config does not get mounted, and therefore some critical initializations like network adapter does not take place (network.cfg file not found error). My other 3 motherboards do not have this problem because I can access them via //tower after boot process is finished.
So I am now trying to figure out why /boot/config does not get mounted during the boot process, I thought as long as the USB drive volume name is 'UNRAID' this should not happen. syslog does not tell me much and I wish there's a way to capture the boot logs.