Using dm_crypt and not finding /dev/mapper/root

[westboy21]

After great efforts I succeeded in encrypting my root filesystem using this guidehttps://forums.gentoo.org/viewtopic.php?t=191052&highlight=

I then decided to encrypt my laptop with the same method. This I got working as well. A month later I'm having issues with devices on my laptop, so I examine my setup. I somehow did all that encrypting without using udev. The guide was specifically FOR udev. I'm not sure if I was drunk or not

So ... I installed udev, and recompiled the kernel and took out devfs support. Now when I reboot, I type my password to decrypt my root partition, my ram drive does the necessary magic, and the real init process takes over. Then checkroot comes into play. Seems it can't find /dev/mapper/root. Why does this not exist? I've compared files on my desktop to files on my laptop till I'm sick of looking at them. There are NO differences. Why is the laptop missing the device at boot?

Can anyone explain to me, how the device transfer works during the pivot_root stage. When the ram drive decryptes the partition, does the /dev/mapper/control and /dev/mapper/root devices get copied over to the real root? If not, then how does the real init process know about them, since these devices are in a different /dev/ directory under the ramdrive. ???

I'm confused.

[mossmann]

I found multipath-tools necessary to get my /dev/mapper/ files working with udev:

https://bugs.gentoo.org/attachment.cgi?id=44249&action=view

I've also read of some people having to introduce a delay to let udev catch up:

https://forums.gentoo.org/viewtopic.php?t=189189