Upgrading Samba 4 by vampire?

[Angelos Oikonomopoulos]

On 11/03/2010 10:49 AM, Angelos Oikonomopoulos wrote:
> Hello all,
>
> for my setup it is likely that I'll have to use virtual machines to run
> Samba 4 as a domain controller. So this gave me the idea of upgrading by
> building a VM with the newer Samba 4 version, joining the domain as a DC
> and then decommissioning the older Samba 4 VM. In particular, since I
> plan to run a redundant setup, I'd like to do that in pairs (i.e.
> joining two new VMs to the domain, then taking out the old ones).
>
> Is this expected to work? Any other considerations I'm not aware of?

I've asked about this on IRC also and Andrew Bartlett advised against 
using vampire to upgrade to a newer Samba 4 version. He was also 
skeptical about my other idea of cloning a Samba 4 VM, upgrading using 
upgradeprovision and then removing the VM with the old Samba 4 version.

Apparently the recommended way to upgrade a redundant Samba4 setup 
involves demoting a server, then upgrading to the newer Samba4 version, 
then re-promoting it, although I'm not yet clear on how to do the 
demoting. I'd be happy to put together an upgrade guide if someone can 
guide me through the demoting procedure.

TIA,
Aggelos