[geeks] Project Etude

[Francois Dion]

On 9/10/07, Jonathan C. Patschke <jp at celestrion.net> wrote:
> On Mon, 10 Sep 2007, Bill Bradford wrote:
>
> > On Mon, Sep 10, 2007 at 12:42:38PM -0500, Jonathan C. Patschke wrote:
> >> However, since the system ID is cached in (true) kernel memory, it's
> >> shared across zones.  In fact, nothing you can do in a zone is
> >> supposed to give you write access to it.
> >
> > You can't run the hostid hack within a zone?
>
> Nope, because it's cached in true kernel memory, which is not writable
> from any but the global zone.

One word: Dtrace



global# ./zhostid &
[1] 8717
global# hostid
12345678
global#
global# zlogin workzone1
[Connected to zone 'workzone1' pts/10]
Last login: Tue Jun 21 03:51:10 on pts/10
Sun Microsystems Inc.   SunOS 5.10      Generic January 2005
#
# hostid
90abcdef

http://www.brendangregg.com/DTrace/zhostid_example.txt
http://www.brendangregg.com/DTrace/zhostid