Infrastructure at your Service

Category Archives: Operation systems

David Barbarin

Windows Failover Cluster : Introduction to paxos tag

By | Database Administration & Monitoring, Operation systems | No Comments

A couple of days ago, I was in charge to install a new SQL Server AlwaysOn and availability group with one of my colleague Nathan Courtine. During the installation, we talked about testing a disaster recovery scenario where we have to restart the Windows Failover cluster in forced quorum mode. Restarting a WSFC in such mode implies some internal stuff especially for the cluster database data synchronization between nodes. The WSFC uses internally the paxos…

 
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Pierre Ochsenbein

VM Linux – Device not found : Network unreachable

By | Database Administration & Monitoring, Operation systems | No Comments

Recently I exported an Oracle Virtual Box VM as an “.ova” file. When the file was imported again I faced issues with the network devices inside the VM. This post is about what I experienced and how I resolved it. In my example I have two networks devices configured for the VM in the Virtual Box: When I logged in I found that eth0 and eth1 are not available: [root@MYSQL ~]# ifconfig lo Link encap:Local…

 
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Georges Grey

Stay tuned with kernel parameters

By | Database Administration & Monitoring, Operation systems | No Comments

Why does the sysctl.conf value for swappiness on Oracle Linux 7.x not survive a reboot For a project I applied the dbi services best practices for Oracle databases. One of these is to adjust the swappiness parameter. We recommend to use a very low for the swappiness value like 10 or even lower to reduce the risk for Linux to begin swapping! Swapping on a database server is not a problem per se, but it generates activity…

 
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David Barbarin

Windows Server 2016: Introducing Storage Spaces Direct

By | Hardware & Storage, Operation systems | 3 Comments

Have you heard about Storage Spaces introduced by Windows Server 2012? Well, this is a very interesting storage feature that allows us to deal with functionalities like storage virtualization, RAID capabilities, thin or thick provisioning, cluster shared volume (CSV), efficiently file repair and so on. In addition, the Windows 2012 R2 version has also introduced some enhancements like storage tiering, write-back caching, datadeduplication, parity space support for failover clusters, JBOD enclosure awareness… A bunch of…

 
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Daniel Westermann

Getting started with Ansible – Preparations

By | Database Administration & Monitoring, Operation systems | No Comments

When your infrastructure landscape becomes larger and larger you definitely need a tool which helps you in managing your servers, no matter if pḧysical or virtual, running in the cloud or not. One tool (many others are around) which assists you in provisioning, configuration management and mass deployment is Ansible. If you look at the man page you can find this sentence: “Ansible is an extra-simple tool/framework/API for doing ‘remote things’ over SSH.”. What is…

 
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David Barbarin

Windows failover cluster 2016 : new site awareness feature

By | Database Administration & Monitoring, Operation systems | No Comments

After my first two blogs about cloud witness and domain-less dependencies features shipped with Windows Server 2016, it’s time to talk about another pretty cool feature of the WSFC : site awareness that will also benefit to our SQL Server FCIs and availability groups. But before to talk further about the potential benefits of this new feature, let’s go back to the previous and current version of Windows Server that is 2012 R2. Firstly, let’s…

 
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Saïd Mendi

Linux – How to check the exit status of several piped commands

By | Operation systems | No Comments

As piping in bash commands is common and very usefull, controling the exit status of each piped commands in bash scripting can be vital, especially for backups. I was checking by a customer the backups of a critical MySQL instance and was surprised even stunned that the return status of all of them was always  successfull when tested but physically on disk, the dumps were all empty. No valid backups since a long time meaning…

 
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Stéphane Savorgnano

Windows Server 2016: Containers

By | Operation systems, Technology Survey | No Comments

One of the new feature which will come with Windows Server 2016 is the Containers. Microsoft made available its fourth technical preview of his Windows Server 2016 platform  some days ago. This new Technical Preview brings with it and for the first time Hyper-V Containers as the Technical Preview three came with the first release of Windows Server Containers. I will discuss about the difference of those two types of Container later in this blog….

 
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Georges Grey

Mail mit Format und Priorität aus Linux

By | Operation systems | No Comments

Ausgangslage Ein Kunde hat mit kürzlich danach gefragt, wie ich den Output eines Scripts auf einer Linuxplattform per Mail sauber formatiert versenden kann. Als Beispiel nehmen wir folgendes: ____________________________________________________________________________________________________________________ File System free space on fed22v1.localdomain ____________________________________________________________________________________________________________________ | | | Mb-Total Mb-Free 0% 20% 40% 60% 80% 100% | | / : 17918 16263 #####—-+———+———+———+———+ 10% | | /boot : 476 326 #############——+———+———+———+ 27% | | /dev : 479 479 +——–+———+———+———+———+ 0% | | /dev/shm :…

 
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Georges Grey

Control-M Application Integrator verwaltet Microsoft PowerShell Code & Credentials

By | Application integration & Middleware, Operation systems | No Comments

Welche Vorteile hat “Control-M Application Integrator”? Bei einem Kunden, der Control-M im Einsatz hat, habe ich auf einem Windows Server ganz viele Windows und PowerShell Scripts angetroffen. Unter diesen Scripts waren einige die nach einem bestimmten Keyword in einem Log-File suchten. Alle diese Scripts hatten einen festen CIFS Path im Script. Damit das klappt, wurde ein Share auf dem Windows Server gemappt, das File nach dem Keyword durchsucht und der Share wieder abgehängt. Dazu wurden…

 
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