Some Tasks stop working after some time

[AR84]

Hi,

I have moved the Zimbra installation from CentOS 6 (Version: zcs-8.6.0_GA_1153) to CentOS 7 and updated to Version zcs-8.7.11_GA_1854.
Everything is working fine for some hours, but then once of a sudden some services fail to be running and emails are not sent anymore.

This morning the following 3 services did not run anymore:
amavis Stopped
amavisd is not running.
antispam Stopped
zmamavisdctl is not running
antivirus Stopped
zmamavisdctl is not running

the rest is running. Restarting the services solved the problem for some hours.

Then some hours later
antivirus, opendkim and snmp did not run anymore.

Does anyone know what could be the cause that some services stop running after some hours?

Also after restarting the above services everything is working just fine... but it is only a matter of hours...

[AR84]

Just again earlier today the "spell" service just stopped, simply starting it again will do the job until some hours later.

Now the stats stopped working and i had to restart it. This way I constantly have to monitor the server. Any idea what the reason could be? On the old server it was running just perfect, just now on the new one the services just stop running... so wierd...

[AR84]

Isnt there anybody that has similar problems?

1-2 times a day different services are crashing. For example now again

amavis Stopped
amavisd is not running.
antispam Running
antivirus Stopped
zmamavisdctl is not running
zmclamdctl is not running
zmfreshclamctl is not running
dnscache Stopped
dnscache is not running.
ldap Stopped
logger Stopped
zmlogswatchctl is not running
mailbox Stopped
mysql.server is not running.
zmmailboxdctl is not running.
memcached Stopped
memcached is not running.
mta Stopped
zmsaslauthdctl is not running
postfix is not running
opendkim Stopped
zmopendkimctl is not running.
proxy Stopped
proxy is not running.
service webapp Stopped
mysql.server is not running.
zmmailboxdctl is not running.
snmp Stopped
zmswatch is not running.
spell Stopped
zmapachectl is not running
stats Stopped
zimbra webapp Stopped
mysql.server is not running.
zmmailboxdctl is not running.
zimbraAdmin webapp Stopped
mysql.server is not running.
zmmailboxdctl is not running.
zimlet webapp Stopped
mysql.server is not running.
zmmailboxdctl is not running.
zmconfigd Stopped
zmconfigd is not running.

Any idea what could be the reason?
On CentOS 6 everything was running fine. Or could it have to do with version 8.7.11 ?

I would be really thankful for any direction i could check.

Which logs should i be able to find information about the crash? I checked mostly all of them in /var/log and in /opt/zimbra/log
but somehome I am not able to find anything indication the problem...

[AR84]

Just as an information, i am running zimbra on a single server