Since update of my UCS DC Master to 4.3 I get the following mail from Cron:
Cron <root@server2> /usr/sbin/univention-samba4-backup
tdb_mutex_open_ok[./private/netlogon_creds_cli.tdb]: Can use mutexes only with MUTEX_LOCKING or NOLOCK
Failed to open ./private/netlogon_creds_cli.tdb
Error while backing up ./private/netlogon_creds_cli.tdb with tdbbackup - status 1
It seems there is already a similar bug for Samba filed: Samba-Bugzilla – Bug 13088.
cu,
Daniel