Best practice to replace an AD DC

[Daniele Dario]

Hi Samba Team,
first off I'd say thanks to everybody who's contributing to the Samba
project because Samba it's both a fantastic work and learning
instrument.

Last week one of the two samba 4 AD DCs of my domain crashed due to an
HDD problem.
Now I'm going to replace the disk and reinstall the OS and the idea is
to re-use the same hostname when ready so I need some advice.

The two DCs are (one were) running samba 4.1.9 and luckily the one which
crashed was not owning any FSMO role so actually the only problem is
that replication is stopped (obviously).

Can I just use the old smb.conf and idmap.ldb before start samba on the
new installation or do I have to force a demote (the server won't boot
without replacing the disk) of the dead DC and than join to the domain
the new one?
Would it be a problem using the same hosstname?

Many thanks in advance for every advice,
Daniele.