I have a DL380 and had the same problem, but I can tell you how to install successfully. :-) BTW, all the "hda=cdrom" and "ide=nomda" options didn't help.
You can't install from CD. Doesn't matter if you have a CD or DVD drive. You always get the "format" error. OTOH, I stuck a SuSE 8.2 disk in and it started installing beautifully. Sigh...if only I didn't have the RH 9.0 requirement.
You can't install by NFS mount either. It won't mount. I set up 2 different machines, dropped the RedHat dirs onto it per instructions, tested the NFS exports to various machines successfully, but the install program would never mount the NFS dir. The error message was generic and useless. I'm starting to dislike RH.
Try 3 was a hard drive install, but I have an empty HD. However, since Suse 8.2 would install, I did a minimal Suse install with a 1G root partition (to be reclaimed later as swap or with LVM), and created a 2.5G ext2 partition, then I dropped the 3 ISOs into it. I mounted that partition as /RH9, so the ISO's would be a the top. I put the ISOs there by sticking each of the CDs in the drive and doing "dd if=/dev/cdrom of=/RH9/cd1.iso bs=512" (ignore the warning/error at the end), changing the filename with the disk number. The ISOs should be something like 667M, 677M, 508M (numbers from memory but that should be close). Once you've done all that, put the RH CD1 back in the drive, boot the machine, pick "hard drive install", you'll get the Welcome Message, an off you go.
If you don't have a SuSE 8.2 disk laying around, you should be able to use any older RH version, as I understand they install too (though I haven't done it). Be sure to make the ISO partition ext2, that's vital.
HTH and Good Luck!
Kevin
