Solaris

Even though zoneadm makes sure that there are no processes
executing in the zone, the unmount operation can fail if processes in the global zone have open
files in the zone. Use the tools described in the proc(1) (see pfiles) and fuser(1M) man pages
to find these processes and take appropriate action. After these processes have been dealt with,
reinvoking zoneadm halt should completely halt of the zone.
(page 410 of the previous pdf link provided)

@ctsgnb: as I already wrote, this command is not documented so pointing to the docs won't help.
Here is where it is "undocumented":
Cross Reference: /onnv/onnv-gate/usr/src/cmd/zoneadm/zoneadm.c

edit: sorry we cross-posted. The troubleshouting chapter you point to is still relevant in the documented case.

@jilliagre ,

I didn't contradict you dude.

I apologize if you felt offended

I just posted that link because i thought that document was an accurate ressource to have for zone management problems in general.

I have also found that it could give some alternate ideas about what could be tried.(halting,shutdown the zone)

I am not a solaris admin but with a quick look at it i have found interesting information (just like the one of my previous post) that - i have tought - could also interest other people so i just shared.

No offense, no problem
That recent and extensive documentation is definitely worth reading indeed.

Thanks for the help just the same.