samba - Oct 2016 - PDC died, broken after reboot

A couple of days ago my PDC died due to a hardware failure. Since I had 
a secondary DC I hoped it would take over silently. Well, it did, but 
not exactly silently. I finally claimed the PDC role for it, which 
apparently worked. But I had to edit the DNS information to remove the 
PDC using the management console. After that the system seemed to work. 
At least I could log in from our Win7 clients.

Now I had to reboot after a power fail. Linux clients using Kerberos and 
LDAP on the new DC still work flawlessly. However after some time the 
system broke. It turned out that the Bind9 DLZ server was not running 
(anymore?) and would not restart, since it lacked reverse domains.

I had a slave server, which had the zones cached. I made this one 
authorative to get the system going again. Logons from Linux work fine. 
But Win7 logins fail.

I meanwhile have the file system of the original DC accessible again and 
could put that into a VM.

Is there any advise how to get the system going again? I'm close to 
scrap it all and restart from scratch.

Thanks for your help,

  - lars.

On Wed, 26 Oct 2016 12:38:54 +0200
"Dr. Lars Hanke via samba" <samba at lists.samba.org> wrote:
> A couple of days ago my PDC died due to a hardware failure. Since I
> had a secondary DC I hoped it would take over silently. Well, it did,
> but not exactly silently. I finally claimed the PDC role for it,
> which apparently worked. But I had to edit the DNS information to
> remove the PDC using the management console. After that the system
> seemed to work. At least I could log in from our Win7 clients.
> 
> Now I had to reboot after a power fail. Linux clients using Kerberos
> and LDAP on the new DC still work flawlessly. However after some time
> the system broke. It turned out that the Bind9 DLZ server was not
> running (anymore?) and would not restart, since it lacked reverse
> domains.
> 
> I had a slave server, which had the zones cached. I made this one 
> authorative to get the system going again. Logons from Linux work
> fine. But Win7 logins fail.
> 
> I meanwhile have the file system of the original DC accessible again
> and could put that into a VM.
> 
> Is there any advise how to get the system going again? I'm close to 
> scrap it all and restart from scratch.
> 
> Thanks for your help,
> 
>   - lars.
> 
> 
> 
I actually had the same problem last week, my first DC died and Bind9
wouldn't start on the second (now only)DC, because it claimed there were
no records in the reverse zone. a quick check showed they were in AD,
but Bind9 wouldn't start, so I deleted the reverse zone and recreated
it. Bind9 now started, so I added the reverse PTR's for the fixed ip
machines, everything is now working okay.

Writing this made me think of a possible reason, the reverse zone was
created on the first DC, so this was probably the only machine in the
reverse zones SOA.

Rowland