Hi, I tried to install gentoo on my AMD 64 dual core machine. It has four 500 GB HDs. I followed the instruction on http://www.gentoo.org/doc/en/gentoo-x86+raid+lvm2-quickinstall.xml. I replaced /dev/md4 with raid5 instead of raid0. Here is the list of each HD's partitiion: /dev/sda: partition #, boot start end type 1 * 1 18 fd 2 19 361 fd 3 362 end fd /dev/sdb partition #, boot start end type 1 1 361 82 2 362 end fd /dev/sdc is the same to /dev/sda, and /dev/sdd = /dev/sdb I created /dev/md1, /dev/md3 and /dev/md4: mknod /dev/md1 b 9 1 mknod /dev/md3 b 9 3 mknod /dev/md4 b 9 4 and then form raid: mdadm --create /dev/md1 --level=1 --raid-devices=2 /dev/sda1 /dev/sdc1 mdadm --create /dev/md3 --level=1 --raid-devices=2 /dev/sda2 /dev/sdc2 mdadm --create /dev/md4 --level=5 --raid-devices=4 /dev/sda3 /dev/sdb2 /dev/sdc3 /dev/sdd2 /dev/sdb1 and /dev/sdd1 forms the swap space mount: mount /dev/md3 /mnt/gentoo mount /dev/md1 /mnt/gentto/boot /dev/md4 is for lvm2 and /usr, /home, /opt and other common unix dir are created there after chroot and emerge, I issued emerge grub and modified /boot/grub/grub.conf default 0 timeout 10 title gentoo root (hd0,0) kernel /boot/kernel root=/dev/md3 and issue grub grub> root (hd0,0) .... grub> setup (hd0) .... grub> root (hd2,0) ..... grub> setup (hd2) ..... grub> quit When I reboot, the kernel issued a panic msg: it says can't read /dev/md/3 or (hd2,0) is invalid device. Any idea what went wrong? Thanks in advance for any suggestion. --HH