Just be aware that not everything works as in Linux, exactly .... as Ocicat has pointed out. Its an emulation. OpenBSD is not Linux.
For untrusted users, you
might find the
ChrootDirectory feature of OpenSSH meets your need for limiting untrusted users -- but that depends on what you need those users to be able to do.
Read this article from the OpenBSD Journal, paying close attention to limitations, caveats, disclaimers, and problems:
http://undeadly.org/cgi?action=artic...20080220110039