Milestone HUP / post-milestone dependency failure?

Question

Ok, I know that's a horrible subject line. Please bear with me.
I've been playing with the dependency mechanisms in b72, and have been unable to get an online milestone offlined by disabling a service upon which that milestone depends.
Disabling cron at the single-user milestone prevents
# svcadm -v milestone svc:/milestone/multi-user:default
from succeeding: svcs -a \*milestone\* shows the multi-user milestone is offline, svcs -xv says why, everything works as advertised.
Dandy.
A slightly different test is to cleanly come up to the multi-user milestone with cron enabled, show that the milestone was reached, and cron is online, and then disable cron.
The milestone is still reported as online, although it has lost a dependency. I guess milestones are... milestones, not states, per se, but it would be nice to demonstrate SMF noticing a subsequent dependency failure.
$ svcs | grep mil
disabled 9:41:17 svc:/milestone/multi-user-server:default
online 9:41:27 svc:/milestone/devices:default
online 9:41:32 svc:/milestone/single-user:default
online 10:48:41 svc:/milestone/name-services:default
online 10:48:51 svc:/milestone/multi-user:default
$ svcadm -v disable cron
svc:/system/cron:default disabled.
$ svcs | grep mil
disabled 9:41:17 svc:/milestone/multi-user-server:default
online 9:41:27 svc:/milestone/devices:default
online 9:41:32 svc:/milestone/single-user:default
online 10:48:41 svc:/milestone/name-services:default
online 10:48:51 svc:/milestone/multi-user:default
I've tried to nudge SMF by calling restart on the mult-user milestone, but no joy:
$ svcadm -v restart svc:/milestone/multi-user:default
Action restart set for svc:/milestone/multi-user:default.
$ svcs | grep mil
disabled 9:41:17 svc:/milestone/multi-user-server:default
online 9:41:27 svc:/milestone/devices:default
online 9:41:32 svc:/milestone/single-user:default
online 10:48:41 svc:/milestone/name-services:default
online 11:26:02 svc:/milestone/multi-user:default
$ svcs -a | grep cron
disabled 10:59:53 svc:/system/cron:default
From this state going all the way down to single-user and then attempting to get back up into multi-user fails, as it should. But that feels a lot like
# init s
# init 3
with fingers crossed.
So, two questions:
Is there a svcadm command that will effectively HUP a current milestone?
Is there no simple way to tell before the fact that a milestone is unreachable, or that a currently achieved milestone will not be achieved next time around?
Thank you for reading this far!
cheers,
kidari

Answer 1

There are characteristics to the dependencies within smf(5): grouping, which has to do with the set of entities and their necessity, and restart_on, which has to do with event propagation across the dependency link. If you use svcs -l on milestone/multi-user:deafult,
you will get:
2 $ svcs -l cron milestone/multi-user:default
fmri         svc:/system/cron:default
name         clock daemon (cron)
enabled      true
state        online
next_state   none
state_time   Tue Jan 11 10:37:15 2005
logfile      /var/svc/log/system-cron:default.log
restarter    svc:/system/svc/restarter:default
contract_id  50
dependency   require_all/none svc:/system/filesystem/local (online)
dependency   require_all/none svc:/milestone/name-services (online)
fmri         svc:/milestone/multi-user:default
name         multi-user milestone
enabled      true
state        online
next_state   none
state_time   Tue Jan 11 10:37:24 2005
logfile      /var/svc/log/milestone-multi-user:default.log
restarter    svc:/system/svc/restarter:default
dependency   require_all/none svc:/milestone/single-user (online) svc:/milestone/sysconfig (online) svc:/milestone/name-services (online) svc:/milestone/sysconfig (online) svc:/milestone/sysconfig (online) svc:/milestone/sysconfig (online) svc:/milestone/sysconfig (online) svc:/milestone/sysconfig (online) svc:/milestone/sysconfig (online) svc:/milestone/sysconfig (online) svc:/milestone/sysconfig (online) svc:/milestone/sysconfig (online)
dependency   require_all/none svc:/system/filesystem/local (online)
dependency   optional_all/none svc:/platform/i86pc/kdmconfig:default (online)
dependency   optional_all/none svc:/network/rpc/bind (online)
dependency   optional_all/none svc:/system/system-log (online)
dependency   optional_all/none svc:/system/utmp (online)
dependency   optional_all/none svc:/application/print/server (disabled)
dependency   optional_all/none svc:/network/nfs/client (online)
dependency   optional_all/none svc:/network/inetd (online)
dependency   optional_all/none svc:/network/smtp:sendmail (online)
dependency   optional_all/none svc:/network/ntp (online)
dependency   optional_all/none svc:/system/filesystem/autofs (online)
dependency   optional_all/none svc:/system/cron (online)
dependency   optional_all/none svc:/system/mdmonitor (online)
dependency   optional_all/none svc:/system/name-service-cache (online)
dependency   optional_all/none svc:/system/power (online)
dependency   optional_all/none svc:/system/rcap (disabled)
dependency   optional_all/none svc:/system/system-log (online)
dependency   require_all/none svc:/system/rmtmpfiles (online)The key part of the line for system/cron is "optional_all/none", which means that ("optional_all") milestone/multi-user does not require cron and can be brought online even if cron is disabled or in maintenance, and that ("none") milestone/multi-user is not restarted for any interruption or activity that might happen to cron.
- Stephen