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Zabbix tries to connect to the wrong database - Fix it now
This article covers how to fix Zabbix error, when Zabbix tries to connect to the wrong database.
Basically, when Zabbix tries to connect to the wrong database, we can simply resolve it by restarting the service.
Zabbix is an open-source monitoring software tool for diverse IT components, including networks, servers, virtual machines (VMs) and cloud services. Zabbix provides monitoring metrics, among others network utilization, CPU load and disk space consumption.
How do I fix Zabbix server is not running?
Zabbix server error due to problems with the firewall.
1. As a root user, we check and confirm whether the firewall is allowing connection to Zabbix Server port which is 10051.
2. If not, then we add the following rule in the configuration file /etc/sysconfig/iptables.
3. Finally, restart the service in order to fix the error.
How to turn off Zabbix server?
To Stop the Service:
1. Use PuTTY to log in as user robomanager to the server where Zabbix is installed.
2. Run the following command to switch to user root: su - root.
3. Run the following command to stop the Zabbix service: systemctl stop zabbix_server.service.
To monitor my zabbix port:
1. In order to test your configuration, access the Monitoring menu and click on the Latest data option.
2. Use the filter configuration to select the desired hostname.
3. Click on the Apply button.
4. You should be able to see the results of your TCP port monitoring using Zabbix.
Where is zabbix config located?
The Zabbix installation process created an Apache configuration file that contains these settings.
It is located in the directory /etc/zabbix and is loaded automatically by Apache.
How does Zabbix proxy work?
Zabbix proxy is a process that may collect monitoring data from one or more monitored devices and send the information to the Zabbix server, essentially working on behalf of the server.
All collected data is buffered locally and then transferred to the Zabbix server the proxy belongs to.
Zabbix Server supported DATABASE ENGINE:
Zabbix Server and Proxy support five database engines:
1. IBM DB2
2. MySQL
3. Oracle
4. PostgreSQL
5. SQLite
Libvirt error Unable to resolve address name or service not known
This article covers tips to fix 'Libvirt error: Unable to resolve address: name or service not known'.
QEMU guest migration fails and this error message appears:
# virsh migrate qemu qemu+tcp://192.168.122.12/system error: Unable to resolve address name_of_host service '49155': Name or service not known
Note that the address used for migration data cannot be automatically determined from the address used for connecting to destination libvirtd (for example, from qemu+tcp://192.168.122.12/system).
This is because to communicate with the destination libvirtd, the source libvirtd may need to use network infrastructure different from that which virsh (possibly running on a separate machine) requires.
To fix Libvirt error: Unable to resolve address: name or service not known:
The best solution is to configure DNS correctly so that all hosts involved in migration are able to resolve all host names.
If DNS cannot be configured to do this, a list of every host used for migration can be added manually to the /etc/hosts file on each of the hosts.
However, it is difficult to keep such lists consistent in a dynamic environment.
i. If the host names cannot be made resolvable by any means, virsh migrate supports specifying the migration host:
# virsh migrate qemu qemu+tcp://192.168.122.12/system tcp://192.168.122.12
Destination libvirtd will take the tcp://192.168.122.12 URI and append an automatically generated port number.
ii. If this is not desirable (because of firewall configuration, for example), the port number can be specified in this command:
# virsh migrate qemu qemu+tcp://192.168.122.12/system tcp://192.168.122.12:12345
iii. Another option is to use tunnelled migration. Tunnelled migration does not create a separate connection for migration data, but instead tunnels the data through the connection used for communication with destination libvirtd (for example, qemu+tcp://192.168.122.12/system):
# virsh migrate qemu qemu+tcp://192.168.122.12/system --p2p --tunnelled
Boot a guest using PXE - Do it now
This article covers how to boot a guest using PXE. PXE booting is supported for Guest Operating Systems that are listed in the VMware Guest Operating System Compatibility list and whose operating system vendor supports PXE booting of the operating system.
The virtual machine must meet the following requirements:
1. Have a virtual disk without operating system software and with enough free disk space to store the intended system software.
2. Have a network adapter connected to the network where the PXE server resides.
A virtual machine is not complete until you install the guest operating system and VMware Tools. Installing a guest operating system in your virtual machine is essentially the same as installing it in a physical computer.
To use PXE with Virtual Machines:
You can start a virtual machine from a network device and remotely install a guest operating system using a Preboot Execution Environment (PXE).
You do not need the operating system installation media. When you turn on the virtual machine, the virtual machine detects the PXE server.
To Install a Guest Operating System from Media:
You can install a guest operating system from a CD-ROM or from an ISO image. Installing from an ISO image is typically faster and more convenient than a CD-ROM installation.
To Upload ISO Image Installation Media for a Guest Operating System:
You can upload an ISO image file to a datastore from your local computer. You can do this when a virtual machine, host, or cluster does not have access to a datastore or to a shared datastore that has the guest operating system installation media that you require.
How to Use a private libvirt network ?
1. Boot a guest virtual machine using libvirt with PXE booting enabled. You can use the virt-install command to create/install a new virtual machine using PXE:
virt-install --pxe --network network=default --prompt
2. Alternatively, ensure that the guest network is configured to use your private libvirt network, and that the XML guest configuration file has a <boot dev='network'/> element inside the <os> element, as shown in the following example:
<os>
<type arch='x86_64' machine='pc-i440fx-rhel7.0.0'>hvm</type>
<boot dev='network'/>
<boot dev='hd'/>
</os>
3. Also ensure that the guest virtual machine is connected to the private network:
<interface type='network'>
<mac address='52:54:00:66:79:14'/>
<source network='default'/>
<target dev='vnet0'/>
<alias name='net0'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
</interface>
Internal error Account getPassword cannot decrypt password to be plain - Fix this Plesk error Now
This article covers how to resolve Plesk error, 'Internal error: [Account :: getPassword] cannot decrypt password to be plain'. It happens when A database user whose password is encrypted can now import and export the domain database after providing the database password.
However this issue is resolved in Plesk Obsidian.
To fix this Plesk error:
1. Updating Plesk via the Plesk interface
Make sure that port 8447 is opened in a firewall. If it is closed and cannot be opened for some reason, use the command-line instructions.
i. In Plesk, go to Tools & Settings and click Updates and Upgrades.
ii. On the Updates and Upgrades page, click Update Components.
iii. Click Continue to begin the update procedure.
2. Updating Plesk via a command-line interface
i. Connect to a Plesk server via SSH (Linux) / RDP (Windows Server).
ii. Run Plesk Installer Update (on Windows Server, start a command prompt as an Administrator):
plesk installer update
By default, Plesk installs updates automatically by means of the Plesk daily task (executed every night), if the option Automatically install Plesk updates is enabled at Tools & Settings > Update Settings.
During the update process:
1. Plesk may go offline for several minutes, if updates require a Plesk restart
2. Websites will stay online
Note: If a service component is going to be updated, its service will be restarted.
To find out what Plesk update is currently installed on the system, go to the Home page > System Overview.
Alternatively, execute the following command in a command-line interface:
plesk version
Unlock a file locked by any process or system - Do it now
This article covers how to unlock a file locked by any process or system.
If everything goes correctly, you will fix this Windows problem without killing the process and – more importantly – without having to reboot the system.
To unlock a locked file in Windows 10?
1. Type the name of the locked file in the field, and click the Search button.
2. Select the file from the search result.
3. Behind the search window, in "Process Explorer," right-click the locked file, and select Close Handle to unlock it.
To Open a Locked File When Another Program Is Using It:
1. Close The Program That Is Using The Locked File.
2. Kill The Program Process Using Task Manager.
3. Turn Off The Preview Pane In File Explorer.
4. Toggle The Folder Process In File Explorer.
5. Launch & Close The Locked File.
6. Restart Your Windows Computer.
7. Use Command Prompt To Delete The File.
Apply Configuration Fails in Nagios Server - Resolve this issue now
This article covers solutions to when Apply Configuration Fails in Nagios Server. This issue happens when the Nagios XI server is unable to resolve the "localhost".
The error message will look like this:
Apply Configuration fails with the following error:
Backend login to the Core Config Manager failed.
An error occurred while attempting to apply your configuration to Nagios Core.
Monitoring engine configuration files have been rolled back to their last known good checkpoint.To resolve this Nagios Problem:
1. Edit your /etc/hosts file and make sure there are localhost entries. For example:
127.0.0.1 localhost.localdomain localhost.localdomain localhost4 localhost4.localdomain4 localhost xi-c6x-x64
::1 localhost.localdomain localhost.localdomain localhost6 localhost6.localdomain6 localhost xi-c6x-x64
2. After making these changes try and "Apply Configuration" from Core Configuration Manager and your problem should be resolved.
