I tried setting up slack 10.2 both according to the guide on this site and the guide that guide linked to and I still get that when I try to set up raid 0. How can I fix this?

I used the sata.i kernel.

Is support for your SATA controllers and software RAID built into your kernel? I'm not terribly familiar with the default slack sata.i kernel.

Please reconsider your decision to use RAID-0. If either hard drive fails, and you don't have a backup, it's all lost. The good drive will only have 64K stripes (or there about) of your files so there's really no chance for recovery.

As for your installation, as Matir essentially said, compile a kernel that includes all the modules you need to see your drives when the kernel loads.

Are your drives SATA? That makes things only slightly more complicated. If you _really_ want RAID-0, just don't do it for /boot and /, that is, make sda1 about 128meg for /boot, sda2 about twice your memory for swap, sda3 about 5 GB for /. Then make sda4 the rest of your drive.

Then install slack with root on sda3, swap on sda2 and sda1 is /boot (use the ext2 filesystem)

After slack is up and running, partition sdb1 to be the same size as sda4 and create your md0 raid0 on sda4 and sdb1. The left over space on sdb, use it for something else, like backups.

going through that will make it real easy to learn/ test as you are not booting off the RAID-0, your just using it (mounted wherever you need it, perhaps /pub?)