Kolab 16 on debian dirsrv vanishes every 30 min

[Gelpi Andrea]

Hi,
	On a debian 8 I installed a Kolab 16.

Yesterday I started using in with 30 users an we discovered that after
about 30 min 389 dirsrv stop working.

I have to:

systemctl restart dirsrv a mail.service

And in error log I notice:

08/May/2018:11:03:19 +0200] - 389-Directory/1.3.3.5 B2015.068.854
starting up
[08/May/2018:11:03:19 +0200] - Detected Disorderly Shutdown last time
Directory Server was running, recovering database.
[08/May/2018:11:03:20 +0200] - slapd started.  Listening on All
Interfaces port 389 for LDAP requests

I cannot find any error in any log.

Where have I to look, and what can I do to debug?

-- 
Gelpi ing. Andrea
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