(5) mkdir gentoo and mount the USB Hardrive

Make and then mount directories to install Gentoo. If you have a different partition schema, or used different file systems, slow down and be careful.

Is the USB Drive already mounted ?

Raspbian probably has already found your USB Hardive and mounted all the partitions on /media/. It is trying to be helpful, but it is not what we want. So we un-mount those partitions.

Lets see what Raspbian has auto mounted on /media/pi so we know what to un-mount

root@raspberrypi:/home/pi# cd /media/pi
root@raspberrypi:/media/pi# ls -l

total 21
drwx------ 3 pi   pi   16384 Jan  1  1970 F92E-0B72
drwxr-xr-x 3 root root  4096 Apr 19 10:09 GENOOT

In my case, it has used UUID to name the swap file. GENOOT appears because I named and labelled the root partition as GENOOT when I used the gparted partition tool

umount /media/pi/F92E-0B72
umount /media/pi/GENOOT

Now we can make the mount points and mount the drives. I have a boot partition on the USB drive as a backup copy only.

mkdir /mnt/genoot
mount -t ext4 /dev/sda2 /mnt/genoot

Because we are going to use the /boot partition off the SD Card, we do not make a directory and mount the /boot partition. If you have a more exotic partitioning scheme, you should make extra mount points and mount those partitions

Next : Install Base System - (Stage 3 tarball)