[Samba] Questions on this upgrade scenario

[Nico Kadel-Garcia]

On Sun, Nov 26, 2023 at 9:05 PM James Johnson via samba
<samba at lists.samba.org> wrote:
>
> Hello!
>
> I've encountered a CentOS 6.10 server running Samba 4.1.0 compiled from
> source running as a Domain Controller in a small office. It's being used
> for some basic AD functionality and sharing folders to a half dozen Windows
> desktops on the local network and everything seems to be running fine. I'd
> like to modernize that setup with Ubuntu 22.04 LTS running the latest and
> greatest Samba 4.19.X from repo but I'm not sure what the least terrible
> option is in my case.

You need to replace this server. CentOS 6 has been obsolete since
November, 2020, and continuing to run security services like Samba
with it exposes you to a number of dangers. CentOS 7 will be obsolete
within the year, I'd strongly suggest jumping to CentOS 9 if you're
staying with CentOS.

If you need a full domain controller with RHEL or CentOS systems, be
aware that the Samba built into RHEL 7, 8, and 9 turn off the full
domain controller features at compilation time. If you want a
contemporary Samba for those, you need to grab a more complete build,
or perhaps use my published RPM building setup from
https://github.com/nkadel/samba4repo/ for RHEL 8 or RHEL 9
compatibility. Those are up to Samba 4.19.3 as of a few days ago.

>    - Backup and Upgrade Samba 4.1.0 to whatever the latest is that I can on
>    CentOS 6.10, join the Ubuntu server as a DC with that Samba same version,
>    demote/retire the CentOS server then upgrade Samba on Ubuntu to the latest
>    and greatest?

I'd suggest you don't try to outsmart yourself by using such obsolete
versions of Samba at any stage you can avoid. If you want a full
domain controller, use a current Ubuntu or look into one of the add-on
Samba repos to get it enabled on CentOS 9 or RHEL 9. Or AlmaLinux 9,
since the CentOS world has gotten weird about licenses and repos.

>    - Backup CentOS Samba 4.1.0 files, setup Ubuntu server with Samba 4.1
>    from repo, restore CentOS Samba 4.1.0 files to new Ubuntu Samba 4.1.0
>    server and then upgrade to latest Samba? Basically would be recovering it
>    there like a DR exercise with the Ubuntu server having the same name, same
>    IP, etc?

Or install a recent enough OS to have a contemporary Samba, activate
them both as domain controllers for the same domain, and turn off the
old one. I've not tried that myself with such old and contemporary
versions of Samba.

>    - Create everything new on the Ubuntu server w/ a new Domain and join
>    all the workstations there?

If you're not strongly invested in RHEL and are more invested in
Ubuntu, this might actually be faster, and a chance to clean up your
old domain.

>    - Other less terrible options that could work?
>
> Thanks!
>
> Jim