Bug 225421

+++ This bug was initially created as a clone of Bug #212121 +++

the cluster.conf is:
...
<resources>
...
 <fs device="/dev/data/mt-daten" force_fsck="0" force_unmount="1" fstype="ext3"
mountpoint="/exports.smb/mt-daten" name="mt-daten" options="acl" self_fence="1"/>
 <fs device="/dev/data/zMuell" force_fsck="0" force_unmount="1" fsid="17217" fsty
pe="ext3" mountpoint="/exports.smb/mt-daten/zMuell" name="zMuell" options="acl"
self_fence="1"/>
...
</resources>
<service autostart="1" domain="storage" exclusive="1" name="storage"
recovery="restart">
...
<fs ref="mt-daten"/>
<fs ref="zMuell"/>
...
</service>
...


if I stop the rgmanger he try
to umount <fs ref="mt-daten"/> before he umounts <fs ref="zMuell"/>
that is not posible.
so he reboot the host.

the correct behavior is to umount <fs ref="zMuell"/> before <fs ref="mt-daten"/>

if he starts the rgmanager do the rigth thing:
he mounts <fs ref="mt-daten"/> befor he umounts <fs ref="zMuell"/>

-- Additional comment from lhh on 2006-10-25 11:58 EST --
The ordering is currently not guaranteed for a list of like-typed resources at
this point.  If you have an ordering dependency between two <fs> resources, the
way to guarantee it (right now) is:

   <service>
     <fs name="foo">
       <fs name="bar"/>
     </fs>
   </service>

If you structure your service this way, bar will always be started after foo but
stopped before foo.

Now, the historical reason for this non-guarantee was the idea that it might be
possible in the future to branch during starting/stopping of complex services -
i.e. perform operations on multiple non-codependent resources in parallel.  For
example, consider a service where two non-codependent scripts are needed which,
although not I/O or CPU intensive, each take five minutes to complete:

  <service>
    <script name="foo"/>
    <script name="bar"/>
  </service>

We could start foo and bar simultaneously, saving just about 5 minutes. 
However, the actual, *practical* use of this is very limited.  More importantly,
however, is the fact that implementation of this functionality is very likely
destabilizing.  Additionally, it would very probably break existing
start-ordering behaviors upon which, no doubt, people have already developed an
expectency.

Additionally, the practical uses of having implicit ordering guarantees vastly
exceed the theoretical "performance gain" which might (at some point) have been
attained by starting resources in parallel.

Therefore, I think we should implement implicit ordering guarantees as described.