Hardware: Mainboard as above, 160 GB SATA drive (boot drive), 120 GB PATA drive (data drive from old pc, will be removed soon) and a dvd-rw. During installation, GRUB maps the SATA drive to hd1 - because the drivers are modprobed after boot. During installation I set grub.conf to boot from hd1,0; according to the current mapping. During boot, GRUB changed its mind and mapped the SATA drive to hd0, the PATA drive to hd1. So it booted the old 32bit kernel without SATA drivers and the kernel paniced because it couldn't mount sda5 on /. Reproducible: Always Steps to Reproduce: 1. Get the hardware mentioned 2. Do normal installation, choose GRUB for your bootloader 3. Set it up as described above. Actual Results: GRUB booted from what udev identifies as /dev/hdc, which is the hd of my old 32bit system containing a fully operational Gentoo Linux - but without SATA drivers. Expected Results: GRUB should have booted from /dev/sda, my newly installed Gentoo Linux on AMD64 Workaround: After getting the GRUB screen, edit the whole section you want to boot to and check which harddrive is the one you _really_ want to boot from (use tab-expansion). After booting from the correct hd, modify your /etc/fstab.
either misconfiguration on your part in terms of bios or grub.conf
