As a little follow-up to Fake The hostid Of A Solaris Zone, and regarding the discussion on the capacity to change the hostid of a Solaris non-global zone, it is interesting to mention these (updated) informations:

  1. The LD_PRELOAD trick proposed before is not a proper option, and is really ugly (and intrusive if you didn't unset it before continuing the execution of a program).
  2. When using Solaris 8 or Solaris 9 Containers, there is a feature called Host ID Emulation from the zonecfg utility which can do exactly that.
  3. Before the introduction of the privileges in a non-global zone with Solaris 11/06 (a.k.a. Solaris Update 3), you must run the DTrace zhostid script (daemon) within the global zone. It is not mandatory to run it from the global zone anymore. Using the appropriate dtrace_user privilege only, you can run it directly from the non-global zone: 
    # zonecfg -z ngzone set limitpriv=default,dtrace_user
# zoneadm -z ngzone boot
# zlogin ngzone
[Connected to zone 'ngzone' pts/5]
Last login: Sat Oct  4 18:57:17 on pts/5
Sun Microsystems Inc.   SunOS 5.11      snv_99  November 2008
# /sbin/zonename 
ngzone
# /usr/bin/hostid
837d47dd
# ./zhostid &
[1] 21506
# /usr/bin/hostid
20a82f32
# ^D
[Connection to zone 'ngzone' pts/5 closed]