Scientific Linux is a Fermilab sponsored, stable, scalable, and extensible operating system for scientific computing based on Red Hat Enterprise Linux. It has even been loaded onto systems at the International Space Station. Two most famous experiments to depend on Scientific Linux are the Collider Detector and DZero experiments at Fermilab and the Large Hadron Collider experiments at CERN.
Below you can find Scientific Linux OpenStack/KVM 64bit qcow2 image based on SL 7.2 (Nitrogen) x86_64 release:
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Trisquel GNU/Linux is an elegant and lightweight Linux distribution, derived from Ubuntu, which uses fully free software system without proprietary software or firmware. Trisquel uses modified kernel from Ubuntu distribution, with the non-free code removed and is listed by the Free Software Foundation as a distribution that contains only free software.
Below you can find Trisquel GNU/Linux OpenStack/KVM 64bit qcow2 image based on Trisquel Mini 7.0 x86_64 release:
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Spotify is a music, podcast, and video streaming service that provides digital rights management–protected content from different record companies. Spotify provides access to over 30 million songs, with more music being added approximately every day including albums, EPs, and singles.
In this article we present how to install Spotify Client on Fedora release 23 from RPM using DNF package manager.
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DNF system upgrade is recommended upgrade method for Fedora 21 and later releases. DNF is a kind of successor for FedUp (FEDora UPgrader), which is now obsolete, not supported any more by Fedora Project and should not be used any longer.
In this article we upgrade from Fedora release 22 (Twenty Two) to Fedora release 23 (Twenty Three) or higher release in few simple steps, using DNF system upgrade method.
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Linux installation process can be simplified by means of Kickstart Installation method, used in Linux distributions like: Red Hat, Debian, Fedora, CentOS, Ubuntu. This method utilizes so called Kickstart File, which describes the configuration, required setup and post installation tasks for Kickstart Linux installation.
Kickstart File can be placed in the remote repository, accesible via NFS, HTTP, FTP, etc…, or can be included in ISO image, which is pretty convenient, especially when we don’t want to or don’t have a possibility to create network repository to store a Kickstart File.
In this tutorial we will download original CentOS 7.2 / RHEL 7.2 ISO image, mount it in the Linux file system, modify it by adding Kickstart File (ks.cfg) and re-pack it to create custom UEFI bootable RHEL 7.2 ISO image using mkisofs command.
Continue reading “Mount | Modify | Edit | Repack | Create UEFI ISO with Kickstart File inside”
Have you ever tried to quickly create USB Boot Disk in Linux and had no dedicated software to create one?
For a long time Linux distributions have come with basic tools like dd utility out of the box. dd command can be used to quickly create USB Boot Disk from the given ISO file without using dedicated tools like unetbootin.
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OpenStack Dashboard Error: Unable to get network agents info often seen in Horizon is a result of Neutron related problems.
Usually the problem is caused by neutron-service failure due to service operation time outs.
The below screenshot presents OpenStack Dashboard Error: Unable to get network agents info:
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OpenStack can use diffirent backend technologies for Cinder Volumes Service to create volumes for Instances running in cloud. The default and most common backend used for Cinder Service is LVM (Logical Volume Manager), but it has one basic disadventage – it’s slow and overloads the server which serves LVM (usually Controller), especially during volume operations like volume deletion. OpenStack supports other Cinder backend technologies, like GlusterFS which is more sophisticated and reliable solution, provides redundancy and does not occupy Controller’s resources, because it usually runs on separate dedicated servers.
In this tutorial we are going to deploy VLAN based OpenStack Mitaka on three CentOS 7 nodes (Controller, Network, Compute) using Packstack installer script and integrate it with already existing GlusterFS redundant storage based on two Gluster Peers.
Continue reading “Install and Configure OpenStack Mitaka with GlusterFS on CentOS 7”
Pretty often after rebooting Controller node or powering it on after shutdown, the Horizon (OpenStack Dashboard) is not responding, but we know that it worked before reboot. This issue may be caused by httpd service (Apache), which entered failed state right after powering on the Controller node.
This results in browser’s connection problem to the Horizon:
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Few times during KVM based OpenStack (Mitaka, Newton) automated installations using packstack we encountered DB synchronization errors.
It turned out, that these installation errors appeared due to slow network and/or poor hardware performance of KVM virtualized hardware used to build OpenStack virtual nodes (Controller, Network, Compute).
Continue reading “KVM OpenStack Error: /Stage[main]/Nova::Db::Sync/Exec[nova-db-sync]”