I've got this error message during Installation right after I have chosen Automation Partitioning -> Keep all partitions and use existing free space:

"Boot partition /boot may not meet booting constraints for your architecture. Creation of a boot disk is highly encouraged."

But what constraints? There's no definition to this error message.

My current 120GB harddisk partition:

c: or hda1 = about 40GB (system for Win XP)
d: or hda2 = about 50GB
e: or hda3 = about 20GB using FAT32
remaining unpartition and i used this for Automatic Partitioning

I tried deleting e: partition to create a larger free space but got the same error message. I supposed it can't be the 1024 cylinder problem? Anyway what does that cyclinder problem means?

What should I do now?

my experience tells me to inore this error. I have had it every time i tried to install Red Hat 8. It works fine for me, after ignoring error.
Hope this helped

A long, long time ago in a Galaxy far away, primitive computers had BIOS that would not boot anything beyond cylinder 1024. This was also back when we had 2 GB and then 8 GB hard drive size restrictions. Since Linux brags that it will run on anything, it keeps this warning for those old machines.

Pretty much any computer since 1997 doesn't have this problem.