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Karsten Lenz

CentOS 8 binary compatible alternatives

By | Database Administration & Monitoring | No Comments

There is a lot of roumors around since it was anounced to switch CentOS 8 from a Downstream Build from RHEL 8 to a Upstream Build for RHEL 8 on December 8th 2020. Many people asked why a second Upstream to Fedora and the way of communication choosen was sub optimal in diplomatic words. Cutting the support date from 31st of May 2029 to 31st of December 2021 brings many people in trouble which has…

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Joël Cattin

Automating Linux patching with Ansible

By | Ansible, DevOps, Operation systems, Security | No Comments

Since the beginning of the year, several vulnerabilities have been discovered in the Linux Kernel as well as in others important and widely-used packages. Among them, there was the famous CVE-2021-3156 affecting the sudo package and allowing any unprivileged user to gain root privileges. This one had a base score of 7.8, which is considered as high. This kind of events demonstrate the importance of having a strong patching strategy to ensure up-to-date softwares and…

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Franck Pachot

Linux perf-top basics: understand the %

By | Cloud | No Comments

By Franck Pachot . Linux kernel has a powerful instrumentation that can be accessed easily. When you want to drill down into your program functions to understand their CPU usage, “perf” is the easiest. It can attach to the processes, sample the CPU cycles, get the symbol name, or even the call stack. And display an histogram of sample counts. This provides an easy profiling tool to understand in which function your program spends its…

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Furkan Suv

SUMA Server Part 2

By | Development & Performance, Operation systems | No Comments

In my previous Blog I wrote how to install and configure SUSE Manager. In this Blog I will go more in the deep like repository management and PXE boot configuration. Configuring repository To syncronize products from SUSE repository, you need configure first the Organization Credentials. To get your username and password for repository you need to go: https://scc.suse.com/ Login with your SUSE Account   Admin -> Setup Wizard -> Organization Credentials -> Add a new…

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Franck Pachot

PostgreSQL on Linux: what is cached?

By | Postgres | No Comments

By Franck Pachot . In a recent tweet I wanted to highlight the importance of knowing what you measure with pgbench, because looking at “Transactions per second” without knowing if you are in shared buffer cache hits, or filesystem cache hit, or storage cache hit, or physical read… is just meaningless: https://twitter.com/FranckPachot/status/1358761092307169282?s=20 The “scale” with the default pgbench tables stores about 15MB per scale value, mostly in the pgbench_accounts table and indexes. The default select-only…

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Furkan Suv

SUSE Manager installation

By | Operation systems | No Comments

In this Blog I will write the requirements and steps to install SUSE Manager Server. Maybe you heard about SUSE Manager but you could not understand why a SUSE Manager Server (SUMA) can help to manage your server environments easier. How can SUMA help you? Without automated processes, the systems management overhead increases, and this leadS to increased costs. Get a complete hardware and software inventory of your systems. Install Software with few clicks to…

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Franck Pachot

Pressure Stall Information on Autonomous Linux

By | Database Administration & Monitoring | No Comments

By Franck Pachot . The Linux metrics that are usually considered for performance monitoring and troubleshooting have many drawbacks and frequent misinterpretations. The recent kernels provide PSI (Pressure Stall Information) which is not enabled by default in Oracle Linux “unbreakable” kernel. However, the kernel is compiled with it. Here is how to enabled it in a newly create Autonomous Linux instance (the Oracle Cloud Linux ,based on OEL 7.9, with no-downtime patching) Check PSI availability…

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Furkan Suv

How to prepare for the SLES 15 Admin certification.

By | Operation systems | No Comments

My Background Since I started at dbi services sa (before 3 Weeks), I was working and preparing for the SUSE Linux Enterprise 15 certification. I had worked with other Linux distributions like CentOS, Ubuntu and Debian on my old employer. With my basic Linux knowledge I was able to administrate Apache and nginx with virtual hosts, SSL Encryption with Let’s Encrypt, installing and configuring MySQL Database, opening/closing ports for services with firewall-cmd, network configuration and…

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Franck Pachot

Oracle Autonomous Linux: cron’d ksplice and yum updates

By | Cloud, Database Administration & Monitoring, Oracle | No Comments

By Franck Pachot . Oracle Enterprise Linux (OEL) is a Linux distribution which is binary compatible with Red Hat Enterprise Linux (RHEL). However, unlike RHEL, OEL is open source, free to download, free to use, free to distribute, free to update and gets free bug fixes. And there are more frequent updates in OEL than in CentOS, the free base of RHEL. You can pay a subscription for additional support and features (like Ksplice or…

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Franck Pachot

Always free / always up tmux in the Oracle Cloud with KSplice updates

By | Cloud, Oracle | No Comments

By Franck Pachot . I used to have many VirtualBox VMs on my laptop. But now, most of my labs are in the Cloud. Easy access from everywhere. GCP There’s the Google Cloud free VM which is not limited in time (I still have the 11g XE I’ve created 2 years ago running there) being able to use 40% of CPU with 2GB of RAM: top – 21:53:10 up 16 min, 4 users, load average:…

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