[Samba] What happens if I turn the DC off?

[Stefan G. Weichinger]

I assume I know it ... but I think this is worth being discussed and 
clarified.

At a customer we have 1 samba DC and 1 samba DM = fileserver.

The DC is supported by a small UPS and the battery in that UPS is 
getting old and tells me to replace it.

While it might be possible to swap the battery "online" I prefer to shut 
the supplied server(s) down and do it offline.

That means turning the DC off.

And now the question(s): will the PCs notice that? Is it possible to use 
network shares etc while the DC is offline for about 10 minutes? Or will 
the PCs hit problems right away?

I understand that logins might fail, sure, but maybe the authenticated 
connections to the DM could be maintained by the DM itself for a short 
period of time?

Sorry if I ask obvious things here or show my misunderstanding ... but I 
never tried that and wonder what happens.

Sure, a 2nd DC would be much better, I know.

And selecting a maintenance window for doing all this will also be possible.

Stefan