Nagios: Simple Oracle Check

For Nagios, many, many Oracle plugins are available for checking database availability and performance. But if you just want to check if the instance is up and running (and not add more complexity), you can use the simple script provided here.

In an earlier post, I showed how to install SQL*Plus on Debian and based on that tutorial, I wrote a little shell script to query a database (I called it

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WMIC on Linux examples

In a previous post I showed how to install the Windows Management Instrumentation (WMI) client for Linux (wmic). In this post, I wish to show a few ways on how to query a Windows-based host using the WMI client.

Using WQL, we can query almost any aspect of the Operating System. Using the available WMI Classes (for example the WMI Win32 Classes), we can easily query performance indicators such as Memory Usage, Disk Usage or the status of a certain process.

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Nagios: Check iSCSI Initiator

In the last few weeks I reworked our internal Nagios configuration and added a few checks to some of our internal servers. Since we do not have a dedicated SAN for our environment, we are using iSCSI as a low-cost storage solution. However, the Microsoft iSCSI Initiator implementation sometimes has trouble connecting to the iSCSI target. As a result, we had to monitor the iSCSI Initiator.

So here is our implementation of check_iscsi for the Microsoft iSCSI Initiator. It uses the iscsicli utility provided together with the iSCSI Initiator and runs on the remote server. To use it, place the following batch file in the scripts/ folder of your NSClient++ installation.

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Hello world

My name is Simon Krenger, I am a Technical Account Manager (TAM) at Red Hat. I advise our customers in using Kubernetes, Containers, Linux and Open Source.


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