Some months ago, I built a small VSAN home lab. Gradualy I expanded the setup - e.g. I moved from a hybrid setup (HDDs and SSDs) to all-flash (SSDs only) to utilize deduplication. Because errors might occur during testing, my NAS is still used as shared storage for the cluster. The HDDs of my NAS were unable to meet …

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2016 seems to be the year of big hardware renewals for me - after completely overhauling my virtual infrastructure, I also needed new hard drives for my NAS after nearly 4 years. NAS, DAS, what? For many years, I have been using D.I.Y. NAS servers for collecting my data and media library on a single host. After I was …

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If you want to combine multiple terminal sessions on one window, multiplexers such as tmux or GNU Screen are useful tools. I have been using screen for 10 years with the following configuration: 1$ cat ~/.screenrc 2# F7+F8 for tab switching 3bindkey -k k7 prev 4bindkey -k k8 next 5 6# disable welcome 7startup_message …

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Using OMD it is possible to setup a working monitoring for checking infrastructure setups just within minutes. But - what monitored OMD-relevant processes? Usually, a OMD site consists of multiple pre-configured services such as: Icinga or Nagios Apache web server Cron service rrdcached (for RRD graphs) npcd …

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Recently I stumbled upon an interesting blog post about monitoring systemd units with Nagios or Icinga. But in my opinion the post's screenshot is misleading. I looks like the linked Python scripts automatically discovers and configures systemd units within Nagios/Icinga - which is not the case. The script named …

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If you need to protect a Linux host against unauthorized access, fail2ban is a very handy service. The application scans log files of various services, automatically detects failed logins and blocks attacker's IP addresses. Especially on public hosts, it is essential to implement a protection like this on prominent …

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When configuring and testing a Python Icinga plugin within an OMD site, I stumbled upon the following error recently: 1TypeError: 'frozenset' object is not callable After some tests on other systems, I found out, that the Python library hashlib shipped with OMD seems to be faulty. Copying the system-wide …

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With this article, I'm starting a blog series I'm really excited about. It's all about VMware's vRealize Orchestrator (vRO) - a very might tool than can simplify a VMware administrator's workaday life heavily. 🙂 What is vRealize Orchestrator? vRO is a utility for automating IT processes around virtual environments. It …

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By default, Enterprise Linux 7 is shipped with Apache 2.4.6 and PHP 5.4. For some current web applications this is way too old as development of PHP 5.4 stalled in fall 2015. During the product life cycle, Red Hat offers 10 to 13 years (Extended Support) maintenance for all packages being part of the distribution - …

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When running Oracle databases under Linux, some additional kernel parameters need to be set. Oracle lists these parameters in the appopriate documentation - e.g. for the most recent version 12c: [click me!] Especially for Enterprise Linux 7 there is a dedicated profile for the tuned service (RPM package …

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