On 09/30/10 12:47, Wei Li wrote:
We did a set of tests to understand how controller domain and guest domain 
configuration info being stored, and how autosave and add-spconfig really works 
together.  T5220 and LDOM 1.3 software are used in this test.
sc>  showhost
Sun System Firmware 7.2.10 2010/07/19 17:13

Host flash versions:
    Hypervisor 1.7.9 2010/07/19 15:51
    OBP 4.30.9 2010/07/16 09:01
    POST 4.30.9 2010/07/16 09:39


It looks to me that any change of resource allocation with LDM command, it will be automatically saved 
somewhere on SP even though ldm list-spconfig -r shows "No autosave configurations".  And looks 
like during system reboot, the latest NOT explicitly saved spconfig will be used as configurations.  And 
until the "NOT explictitly saved spconfig" is saved manually with add-spconfig, the tag will always 
be "NEXT POWERON" instead of [CURRENT].

Below is what we get
Right after LDOM manager installed:
ro...@ldommaster LDoms_Manager-1_3>  ldm list
NAME             STATE      FLAGS   CONS    VCPU  MEMORY   UTIL  UPTIME
primary          active     -n-c--  SP      64    32640M   0.1%  9m
ro...@ldommaster LDoms_Manager-1_3>  ldm list-spconfig
factory-default [current]

Perform configuration: add-vds/set-vcpu/set-memory to controller domain
ro...@ldommaster />  ldm list
NAME             STATE      FLAGS   CONS    VCPU  MEMORY   UTIL  UPTIME
primary          active     -ndcv-  SP      8     8G       0.5%  43m
ro...@ldommaster xml>  ldm list-spconfig -r
No autosave configurations

You haven't specified a "current" spconfig name yet, so the current
autosave is being saved under a "special" name that isn't being
displayed.  You should be able to see the contents under:
/var/opt/SUNWldm/autosave-_Default_SP_Config

Once you've set a "current" spconfig (either by doing a add-spconfig or
by booting on a named spconfig), you will see the autosave name when
you do a 'ldm list-spconfig -r' command.

So, right here, had you done:
ldm add-spconfig MYCONFIGNAME

You should have seen:
ldm list-spconfig
factory-default
MYCONFIGNAME [next poweron]

And:
ldm list-spconfig -r
MYCONFIGNAME

ro...@ldommaster xml>  ldm list-spconfig
factory-default [next poweron]

I think this is caused by the ldmd database doing some config
mods at start-of-day.  See Note 2 below.

Reconfiguration reboot:

Reboot or power cycle?  A reboot doesn't get a new spconfig, it
simply reboots on the original spconfig.  To clear the [next poweron]
you have to power cycle.

ro...@ldommaster />  ldm list
NAME             STATE      FLAGS   CONS    VCPU  MEMORY   UTIL  UPTIME
primary          active     -n-cv-  SP      8     8G        13%  6m
ro...@ldommaster />  ldm list-spconfig
factory-default [next poweron]

So even though no spconfig was explicitly saved, when server is up, it picks up 
latest configuration, but the flag still kept as [next poweron]
>
As that being said, we simulated controller domain OS got corruption scenario, 
in which case controller domain has to be rebuilt.  Before controller domain 
was rebuilt, one guest domain state is running, the other was inactive.  After 
reinstallation of controller domain completed and LDOM manager 1.3 reinstalled, 
we are seeing one guest domain state is still  showing as running.  The other 
guest domain could not be found any more.  So the question here is:  what 
exactly information is being saved on spconfig and what is being saved in 
/var/opt/SUNWldm.

Our understanding is:
controller domain and running guest domain information is automatically saved 
on SP.
The other guest domains (inactive) will be saved under 
/var/opt/SUNWldm/autosave*.

Is above correct?

No, there are several issues here.

1. ldmd does not automatically update configurations on the SP.  ldmd
keeps its own internal "current" config which is more or less
mirrored in the autosave configuration.  When ldmd's configuration
is the same as the booted on SP config, if you do 'ldm list-spconfig'
it will show as [current].  If you modify that config, i.e. the internal
ldmd config is different than the SP config, 'ldm list-spconfig' will
show it as [next poweron], which unfortunately is somewhat misleading
in this case, as you're not going to necessarily get the "updated"
config on next poweron unless you do an 'ldm add-spconfig'.  Also
note that "factory-default" cannot be modified on the SP.

2. The information about the state of all guests is in the ldmd
database: /var/opt/SUNWldm/ldom-db.xml, which is separate from the SP
configs and autosave configs.  I'm not 100% sure, but I think some state
information within the database is causing the ldmd internal config
for the booted "factory-default" config to be modified at start-of-day
in the case above, and that's why you're seeing it marked as
[next poweron] after reboot.

3. The autosave information is updated at the same time as the internal
ldmd "current" config is updated.  But, again, to see it via
'ldm list-spconfig -r', it has to be an explicitly named spconfig,
via 'ldm add-spconfig <name>'.  I think this would all be much clearer
had you simply done the 'ldm add-spconfig MYCONFIGNAME' suggested above,
as "factory-default" ends up being special-cased for several things.

Hope this helps.

Mike
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