Eject boot medium from Alpine Linux installer
When booting the Alpine Linux installer ISO, the modloop is directly loop-mounted from it and prevents the umounting of it. Just umounting the modloop results in the kernel modules being inaccessible.
This is a quick cheatsheet how to copy the modloop into ram:
First, find the path of the modloop:
localhost:~# losetup -a
/dev/loop0: 0 /media/sdb/boot/modloop-vanilla
Copy it into the rootfs, which is in RAM:
cp /media/sdb/boot/modloop-vanilla /
Umount the disk-backed modloop:
umount /dev/loop0
And mount the copy in RAM in its place:
mount -o loop /modloop-vanilla /.modloop
Finally, umount the boot disk:
umount /media/sdb