[Samba] Primary DC migration / upgrade

[Rowland Penny]

On Tue, 2021-12-07 at 16:02 +0000, Krzysztof Kucybała via samba wrote:
> Hi all,
> I'm contemplating a possible change to my home domain that currently
> spins off a primary dc running on a virtualbox VM. I want to buy a
> very simple set of components to build a cheap tiny yet physical
> server to host the dc.

You could do what I do, run your Samba AD DC's on raspberry pi 4b's and
use Louis Van Belle's Samba repo, see here:

https://apt.van-belle.nl/

>  When that happens, what would the correct approach be towards
> migrating? Does the below make any sense assuming the new physical
> will run Debian Bullseye which has a slightly newer samba version
> compared to the current VM running Debian Buster:
> 
>   1.  connect the new physical box as secondary domain controller ->
> I would assume this will cause it to replicate whatever is in the
> primary

Correct.

>   2.  switch their roles so that vm becomes secondary, physical
> becomes primary

Nearly, except there are no primary or secondary DC's in AD, they are
all just DC's and any DC can hold the FSMO roles. In fact, if you have
seven DC's, they could each hold an FSMO role. So which would be the
'primary' ??

>   3.  turn off the VM leaving just one DC in the domain (or not, not
> sure if it's worthwhile to keep a secondary DC in a domain as small
> as mine)

You would have to demote the old DC, not just turn it off and it is
always better to have more than one DC.

> 
> Is this going to work, and if so - is this the recommended approach? 

Yes and yes.

Rowland