...

Thread 1 (Thread 0x7f738b21c700 (LWP 19394)):

...

#1 0x0000000000501d30 in mdb_search (op=0xc3a020, rs=0x7f738b21ba30) at search.c:720 scopeok = 1 edata = {mv_size = 0, mv_data = 0x7f74bbb99728}

This indicates that the entry being debugged is actually zero bytes, i.e. it's not a valid entry at all. Nodes like this get stored in the database during slapadd when a child entry gets added before its parent; a zero-byte stub is stored as a placeholder for the missing parent. When you ran slapadd you should have seen warning messages about missing entries, telling you that your LDIF is incomplete.

Yes you are right, I repeated the import via slapcat to test and got this error message:

~ # slapadd -w -q -f /etc/openldap/slapd.conf -l /backup.ldif 50f98421 mdb_monitor_db_open: monitoring disabled; configure monitor database to enable -#################### 100.00% eta none elapsed 09m18s spd 4.6 M/s Closing DB...Error, entries missing! entry 1156449: cn=1356155776-83002,ou=... ,... ,ou=root

(I shortened the entry DN in output with "...")

I recognized this message before, but thought the entry was not imported ...

We can prevent the SEGV but your database is still invalid because your LDIF is invalid.

Yes, will ask in the mailing list for additional information not directly releated to this SEGV.

Thanks

Kindly regards Maike