Comment 1 for bug 133892

I can confirm this bug on toshiba g20.

It seems that when ata_piix is loaded before ahci, ahci module will not see harddrives correctly.
This helps from initramfs shell:

rmmod ata_piix
rmmod ahci
modprobe ahci
exit

I resolved the problem by blacklisting ata_piix module in initrd image. It seems it is latter loaded correctly (latter in boot, when system already chrooted)

Also it seems it is duplicate of bug: #139790