Zabbixserver is not running what to do?I have seen many posts with questions about thismessage, especially those who are starting with monitoring or even those whohave used the tool for a long time, so I decided to record some important tipsto help solve this problem. In today's post I will talk about the possible causes of this error message that indicates unavailability of Zabbix Server.To begin with, keep in mind that you will needbasic Linux knowledge and privileged access to Zabbix Server by command line asroot.In this first step I will list possible causesand then a brief description to clarify better, I suggest to observe everydetail calmly, because even an incorrect letter can affect the service.Possible Causes Incorrectinformation in the zabbix_server.conf configuration file Problemsin database creation and permissions Problemswith firewall or selinux Lackof sufficient resource and processes to start the zabbix_server daemon Networkoscillation when using separate components Virtualization with a lack of resource and without proper configurationSo far we know of some possible causes, nowlet's identify the problem and then make some solutions.1. Zabbix Server LogsThis is the first step that should be checkedregardless of the situation, always view the logs, from the moment the errormessage appeared in the zabbix web interface always view the log.To check the Zabbix log, enter the command asshown below.Note: The log path may change according to theinstallation, to be sure of the path see in the configuration file zabbix_server.conf2. Check the DatabaseThe database is one of the main components, init will be stored all the information that will be collected, therefore itsoperation is fundamental. Zabbix log error message indicating that mysql is not running. This can be applied to other databases. (Postgres,Oracle,IBM DB2,SQlite)Verifythat the mysql service has started correctly or check the logs for mysql. Database access permissions canalso be the cause after installation, if this error message appears verify thatthe permissions have been madeYoumust enable the permissions for the user "zabbix" to access thedatabase3. Check for possible blockagesFirewall is our first point to be verified, yeswe need to check whether or not there are firewall rules preventing the use ofthe service, on the other hand also depending on the operating system, we canhave SELINUX which by the way is an additional method of security for Linuxenvironments Based on user and process and in most cases are disabled by someadministrators, we will not go into details in this post let's just talk aboutpossible causes. Firewalld running SELINUX activeSuggestionsIn CentOS / RedHat 6, you can disable thefirewall by following these instructions: http://www.cyberciti.biz/faq/fedora-redhat-centos-5-6-disable-firewall In CentOS / RedHat 7, you can disable thefirewall by following these instructions: http://www.liquidweb.com/kb/how-to-stop-and-disable-firewalld-on-centos-7You may also need to disable SELinux on CentOS /RedHat. Please follow these instructions: http://www.revsys.com/writings/quicktips/turn-off-selinux.html ou http://aruljohn.com/info/centos-selinux/4. Resource Allocation IssuesInitially Zabbix Server has several processesfor the application to work correctly, following the screen indicating possibleproblems with the "CacheSize" parameter of the configuration file zabbix_server.conf.Inthis case we must adjust the parameter "Cachesize" and increase in away that the Zabbix Server application can make the most of the memoryresource.Note:Always see the log and after making any adjustments to the configuration fileit is necessary to