Adding encrypted drive to encrypted system post installation

[Ralf Ertzinger]

Hi.

On Sat, 26 Sep 2009 11:36:28 +0100, Tim Waugh wrote

> I'm not clear on how the existing encrypted partitions get unlocked
> but I think perhaps dracut does it?  I get prompted for the encryption
> password during boot.

I have a similar, but slightly different question. I have used an
encrypted partition for some time now (before anaconda grew support
for this), containing /home (so / is not encrypted). I get prompted
for the password on boot, but the 'prompt' mainly consists of plymouth
switching back to a text console. I know that I am supposed to enter
the passphrase at this point, and it all works, but from the quoted
text above I suspect that there is a 'pretty' prompt for this,
too.

What do I have to do to get this prompt?