Hello,
I have problems starting the services bind9 and samba4 which are stopped on my AD-DC. When I try to start samba4, nothing happens. When I start bind9, I get an error message
Loading 'samba4.zone' using driver dlopen
Nov 15 14:23:45 ucs-hohn named[7243]: samba_dlz: ldb: ltdb: tdb(/var/lib/samba/private/sam.ldb.d/CN%3DSCHEMA%2CCN%3DCONFIGURATION%2CDC%3D****MY___DOMAIN****%2CDC%3DINTRANET.ldb): tdb_rec_read bad magic 0x0 at offset=8234316
samba_dlz:
Nov 15 14:23:45 ucs-hohn named[7243]: samba_dlz: ldb: module samba_dsdb initialization failed : Operations error
Nov 15 14:23:45 ucs-hohn named[7243]: samba_dlz: ldb: Unable to load modules for /var/lib/samba/private/sam.ldb: Unable to load ltdb cache records for backend 'ldb_tdb backend'
Nov 15 14:23:45 ucs-hohn named[7243]: samba_dlz: Failed to connect to Failed to connect to /var/lib/samba/private/sam.ldb: Unable to load ltdb cache records for backend 'ldb_tdb backend': Operations error
Nov 15 14:23:45 ucs-hohn named[7243]: samba_dlz: FAILED dlz_create call result=25 #refs=0
Nov 15 14:23:45 ucs-hohn named[7243]: dlz_dlopen of 'samba4.zone' failed
Nov 15 14:23:45 ucs-hohn named[7243]: SDLZ driver failed to load.
Nov 15 14:23:45 ucs-hohn named[7243]: DLZ driver failed to load.
Nov 15 14:23:45 ucs-hohn named[7243]: loading configuration: failure
Nov 15 14:23:45 ucs-hohn named[7243]: exiting (due to fatal error)
Nov 15 14:23:45 ucs-hohn systemd[1]: bind9.service: Main process exited, code=exited, status=1/FAILURE
Nov 15 14:23:45 ucs-hohn samba4[7244]: rndc: connect failed: 127.0.0.1#953: connection refused
Nov 15 14:23:46 ucs-hohn samba4[7244]: rndc: connect failed: 127.0.0.1#953: connection refused
Nov 15 14:23:47 ucs-hohn samba4[7244]: rndc: connect failed: 127.0.0.1#953: connection refused
Nov 15 14:23:48 ucs-hohn samba4[7244]: rndc: connect failed: 127.0.0.1#953: connection refused
I’m not sure if samba can’t start because bind is missing, or vice versa. Somehow I wonder if I can restore (obviously corrupted) sam.ldb
When I try r reprovisioning the Samba like in https://help.univention.com/t/re-provisioning-samba4-on-a-dc-master/34, I can’t get the error message
ltdb: tdb(/var/lib/samba/private/sam.ldb.d/CN%3DSCHEMA%2CCN%3DCONFIGURATION%2CDC%3D****MY___DOMAIN****%2CDC%3DINTRANET.ldb): tdb_rec_read bad magic 0x0 at offset=8234316
Failed to connect to 'tdb:///var/lib/samba/private/sam.ldb.d/CN%3DSCHEMA%2CCN%3DCONFIGURATION%2CDC%3D****MY___DOMAIN****%2CDC%3DINTRANET.ldb' with backend 'tdb': Unable to load ltdb cache records for backend 'ldb_tdb backend'
module samba_dsdb initialization failed : Operations error
Unable to load modules for /var/lib/samba/private/sam.ldb: Unable to load ltdb cache records for backend 'ldb_tdb backend'
Failed to connect to /var/lib/samba/private/sam.ldb - Unable to load ltdb cache records for backend 'ldb_tdb backend'
so I can’t get the value for rIDNextRID
I hope somebody has a hint for me, otherwise i have to reinstall everything 
Thanks in advance
Christoph