[Samba] AD Schema Upgrade from 2003 to 2008_R2

[Andrew Martin]

Hello,

A long time ago, I ran "samba-tool domain level raise --domain-level=2008_R2" 
to raise the domain Functional Level of my Samba AD from 2003 to 2008_R2. At 
the time, I don't think the "samba-tool domain schemaupgrade" command existed, 
or at least it wasn't included in these instructions on how to raise the 
Functional Level:
https://wiki.samba.org/index.php/Raising_the_Functional_Levels

Now I'm looking at raising the Schema Level and Functional Prep Level from 
2008_R2 to 2012_R2 (but not the Functional Level since I know 2012_R2 isn't 
supported yet) and following this step:
https://wiki.samba.org/index.php/AD_Schema_Version_Support#Live_Upgrade

However, I am wondering if the schema changes from 2003 to 2008_R2 were never 
applied since that was a manual process of specifying adprep LDIFs (which I 
did not do when upgrading from 2003 to 2008_R2).

So related to this, I have the following questions:
* is there a way to easily check if the schema changes from 2003 to 2008_R2 
  were already successfully applied? My DC says that objectVersion is 47, but 
  I wonder if that attribute was just updated by raising the Functional Level 
  but the schema is not actually updated?

* should I run "samba-tool domain schemaupgrade --ldf-file=sch31.ldf" and 
  similar for sch31.ldf through sch47.ldf to ensure that my current 2008_R2 
  instance is actually up-to-date? Will this do any harm (e.g. is applying 
  these twice harmful or is it a problem when the domain thinks it is already 
  on Functional Level 2008_R2)? 

* am I correct in understanding that once on 2008_R2 I should run these 
  commands in this order to upgrade the schema from 2008_R2 to 2012_R2?
    samba-tool domain schemaupgrade --schema=2012_R2
    < restart samba-ad-dc >
    samba-tool domain functionalprep --function-level=2012_R2

* is there any harm in running the sch31.ldf through sch47.ldf files on a 
  domain that has already had the above commands run on it to upgrade to 
  2012_R2 (in other words, is it harmful to apply these LDIFs in the wrong 
  order)?

Thanks for the guidance on how to successfully (and safely) do this.

Andrew