Category Archives: Linux Administration

LVM Remove physical volume from volume group

LVM provides flexibility to organize logical volumes without being bound to inflexible partitioning. If set-up correctly, the LVM can grow as the disk/raid might grow. To allow the LVM to grow, the block device needs to be added as a … Continue reading

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Docker container on RHEL fails to start without error

Recently a Docker container refused to start for me without any hint about why in the OS or Docker container’s logs. It turns out that SELinux jumped in and blocked access without logging its interference. Containers which were running in … Continue reading

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Setup LVM and create logical volume

Creating an LVM on a disc / partition allows for a lot of flexibility in managing the storage. Managing a disc using LVM consists of a number of steps, from preparing the disc itself until mounting a volume. With LVM … Continue reading

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Extend logrotate for additional log files

The Linux operating system consists of many different components. Many of them log their activity directly or indirectly into log files. Over time those log files grow and would eventually fill up the disk if there wasn’t a utility like … Continue reading

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Manage SELinux boolean policies

Configuring a new service often means dealing with SELinux. The easiest way is most of the time to set an SELinux boolean. But what are SELiunx booleans and what exactly do they do? I will try to shed a little … Continue reading

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Find and extract one file from rpm package

Extracting a configuration file (or any other single file) from a package which is not installed is not a standard operation on rpm based systems, but with the following few steps, a file can be extracted without installing the package … Continue reading

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Align a partition on a hard disk

New disks need to be prepared for use. When using a hardware raid like explained in Create hardware raid on HP via hpacucli some partitioning tools even show an error message. To prepare a disk for use, the disk needs … Continue reading

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Mount raw image of entire disc

Raw disc images are very common, they include things like images created using dd for backups and virtual machine disk images. To access the disc image content means the disk image needs to be mounted. Images from a partition can … Continue reading

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Testing environment setup using Vagrant

Setting up a test environment with many different operating systems and versions can be a time consuming task. Installing the different operating systems and configuring them for tests or development can take up a lot of time. Vagrant makes this … Continue reading

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Create hardware raid on HP via hpacucli

Configuring a new hardware raid on a HP server can be done comfortably from the Linux command line without restarting the server. HP provides a small command line tool for this job. The following shows how this tool can be … Continue reading

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