1. Introduction

Zones currently when booted through zoneadm(1M) end up at the
traditional run-level "3" or the equivalent System Management Facility,
smf(5), milestone of svc:/milestone/multi-user-server:default.

There are a number of cases where being able to boot a zone into
single-user mode would be useful including being able to repair a zone
that will not boot or for booting a zone with just enough context so
that a global zone process enter the zone via facilities such as
zlogin(1) and execute some other process.  This latter functionality is
the method the Solaris patching software will use to install patches in
a zone by booting up installed, but not running zones into single-user
mode so that they can be patched by executing the patchadd(1M) from
within the zone itself.

2. Proposal

An optional subargument will be available to the "boot" subcommand of
zoneadm(1M) to specify that this particular boot should be a
single-user mode boot.  For compatibility with what customers expect,
"-s" will be introduced for this purpose.  Other relevant boot
arguments (see kernel(1M)) can be introduced in the future.

	global# zoneadm -z myzone boot -s

			Interfaces Exported
			-------------------

Interface		Classification		Comments
---------		--------------		--------
-s subargument		Evolving		Boots zone single-user
to "zoneadm boot"

The following is the proposed changes to the zoneadm(1M) man page:

@@ -41,8 +41,15 @@

      The following subcommands are supported:

-     boot  Boot (or activate) the specified zones.
+     boot [boot_options]
+           Boot (or activate) the specified zones.

+           The following boot_options are supported:
+
+           -s    Boots only to  milestone  svc:/milestone/single-
+                 user:default.  This  milestone  is equivalent to
+                 init level 's'. See svc.startd(1M) and init(1M).
+
      halt  Halt the specified zones. halt  bypasses  running  the
            shutdown  scripts inside the zone. It also removes run
            time resources of the zone.

A release binding of Patch is requested.