[CentOS] AHCI at boot?

Sat Dec 20 16:35:26 UTC 2008
Joseph L. Casale <JCasale at activenetwerx.com>

>So I'm wondering what config files I need to tweak, to help the
>already installed system use the "new" ahci controller?  Previously,
>it appears to have been using the piix module to access the drive with
>the root fs on it.

So, you need modprobe.conf to reflect this as well as a new initrd.
On a similar system I have from Asus my modprobe.conf looks like this:

alias scsi_hostadapter ata_piix
alias scsi_hostadapter1 ahci

I assume the ata_piix is still required for the jmicron ide controller.
After editing this, run mkinitrd which will look there and then load the
required modules.