jail and emulators/linux_base

Hi all,

I'm running CURRENT and set up a jail where I want to install SUN JDK
1.4.2. In the process, linux emulation needs to be installed. While
installing emulators/linux_base, I get the following:

===> Installing for linux_base-7.1_5
Un-mounting linprocfs...
umount: retrying using path instead of file system ID
===>  Generating temporary packing list
===> Checking if emulators/linux_base already installed
mknod: /compat/linux/dev/null: Operation not permitted
*** Error code 1

While Linux-emulation is already up and running on the host-machine, it
seems the jail is not allowed to create what it needs to run it. I
understand allowing mknod(8) within a jail is dangerous in the case where
you allow untrusted users to be root. Is there some way to either say "I
don't let untrusted users be root" thus allowing this or to compile
emulators/linux_base more jail-friendly, possibly setting things up from
outside the jail?

About compiles, btw, they seem to drag out forever in a jail. Especially
configure takes ridiculous long time. I was under the impression that the
overhead of running a jail should be very small, yet compiling
shells/bash2 in a fresh jail took 8 minutes and 8.6 seconds while
compiling it on the host system took 54.9 seconds. Are there options that
may affect jail-performance I can tune?

Cheers

  Niklas Saers