We have an AD domain (based on old Samba 4.1.9), and currently in LDAP database we have some errors, which samba-tool dbcheck cannot fix. for example: ----------------------- samba-tool dbcheck --fix (.... many similar errors ...) ERROR: parent object not found for DC=SAMG62\0ADEL:ccc70e60-4086-49b0-86f0-e5b4af86666d,CN=Deleted Objects,DC=Domai nDnsZones,DC=dc,DC=samges,DC=ru Move object DC=SAMG62\0ADEL:ccc70e60-4086-49b0-86f0-e5b4af86666d,CN=Deleted Objects,DC=DomainDnsZones,DC=dc,DC=samg es,DC=ru into LostAndFound? [YES] Renamed object DC=SAMG62\0ADEL:ccc70e60-4086-49b0-86f0-e5b4af86666d,CN=Deleted Objects,DC=DomainDnsZones,DC=dc,DC=s amges,DC=ru into lostAndFound at DC=SAMG62\0ADEL:ccc70e60-4086-49b0-86f0-e5b4af86666d,CN=LostAndFound,DC=DomainDnsZ ones,DC=dc,DC=samges,DC=ru Set lastKnownParent on lostAndFound object at DC=SAMG62\0ADEL:ccc70e60-4086-49b0-86f0-e5b4af86666d,CN=LostAndFound, DC=DomainDnsZones,DC=dc,DC=samges,DC=ru ERROR: missing GUID component for lastKnownParent in object DC=SAMG146\0ADEL:c1531dae-eb09-4d2b-8270-4e91b73a6cad,C N=LostAndFound,DC=DomainDnsZones,DC=dc,DC=samges,DC=ru - CN=Deleted Objects,DC=DomainDnsZones,DC=dc,DC=samges,DC=ru unable to find object for DN CN=Deleted Objects,DC=DomainDnsZones,DC=dc,DC=samges,DC=ru - (No such Base DN: CN=Dele ted Objects,DC=DomainDnsZones,DC=dc,DC=samges,DC=ru) Not removing dangling forward link Segmentation fault ------------------------- If I join a newer samba (for example, 4.4.7) as a DC to our domain, transfer roles and demote an older DC, is this error replicate to it? I cannot figure how to fix it, and upgrade is needed anyway. And second question about samba-tool dbcheck - where are a manual/description for options? In man samba-tool it very short: https://www.samba.org/samba/docs/man/manpages/samba-tool.8.html COMMANDS dbcheck Check the local AD database for errors. delegation ...... But it has a many options, like: samba-tool dbcheck --cross-ncs --fix --yes samba-tool dbcheck --cross-ncs --reset-well-known-acls --fix Or it has an option to run with individual tests. What are meaming --cross-ncs, --reset-well-known-acls and other (where is full list)? -- Mike Lykov, system administrator