OK, thank you, that got me onto the right track, now I think I know what
the problem is: mount_mfs.
/sbin/mount_mfs -s 90000 swap /mnt
Is there a way to have devices under that mountpoint?
Of course, just mknod(8) them (each time after creating the mfs),
Thanks everybody for your help. For whatever reason it did not work (for
me) to just copy (pax) the /dev/* files from / to my ramdisk-mountpoint
(/mnt). The files were there but always caused a "failed to open" error
when used from within the chrooted environment. It also did not work to
first chroot and then (within the chroot environment) create the files
with mknod.
What worked was first creating the files with mknod and then chroot.
I don't know why this is so, but I'm happy with it.