Troubleshooting
You got 99 problems? This range of troubleshooting articles will help you reducing them. From securing your Linux systems up to standard system administration tasks.
Troubleshooting CPU usage
Articles and information about troubleshooting system performance issues with focus on CPU usage.
Summary
Got a busy system that comes to a halt due it being too busy? In this article we look at troubleshooting issues related to CPU usage. Monitoring CPU usage The tool top might be the most familiar tool to monitor CPU or memory usage. A good alternative is the pidstat tool. It can be using an interval and easily show active processes, followed by a summary. # pidstat 3 Linux 6.
Network
Articles and information about troubleshooting network performance issues and monitoring network statistics
Summary
Network connectivity starts at a device that links the system to a network, and for Linux systems that is no different. Depending on the physical layer, such as Ethernet of Wi-Fi, the transactions between be better or worse. Besides physical limitations, there is congestion and packet loss that may introduce issues. In this section we look at troubleshooting network performance issues, tooling, and examples. Interfaces The first step is to learn what links we have towards the network.
Troubleshooting guide for Lynis
Troubleshooting Lynis. This document helps with solving most common issues experienced when running Lynis.
Summary
Troubleshooting Lynis This document helps with solving most common issues experienced when running Lynis. Common Lynis errors No hostid and/or hostid2 found Some systems do not have the OpenSSH server package installed. In this case, the hostid2 value may be missing. During the upload it may result in an error. Error: No hostid and/or hostid2 found. Can not upload report file. To see what Lynis discovered, use the show command.
Tuning auditd: high-performance Linux Auditing
To achieve better performance with a auditd configuration, it needs to be tuned. See performance boosters like events exclusion, rule ordering, and more.
Summary
The Linux Audit framework is a powerful tool to audit system events. From running executables up to system calls, everything can be logged. However, all this audit logging comes at the price of decreased system performance. Let’s have a look at how we can optimize our audit rules. Performance tips Good auditd performance will reduce stress on the Linux kernel and lower its impact. Before changing anything to your system, we suggest benchmarking your system performance before and after.
Linux Audit Framework 101 – Basic Rules for Configuration
The Linux audit framework is a very powerful tool to monitor files, directories, and system calls. Learn how to configure it.
Summary
Starting with Linux auditing can be overwhelming. Fortunately, there is a great feature in the Linux kernel to watch events and log them for us. To give you a quick start to use the Linux Audit Framework, we have collected some basic rules for configuring the audit daemon and its rules. Main Configuration By default the configuration values in /etc/audit/audit.conf are suitable for most systems. If you know your system is very low or very high (e.