Posts By: jonny

Mount Files Virtually via Dell iDRAC

Use fallocate to create a new 300 MB file : fallocate -l 300M disk_image.img Create an ext4 file system within the image file: mkfs.ext4 disk_image.img Create a mount point: mkdir /mnt/disk_image mount it: mount -t auto -o loop disk_image.img /mnt/disk_image Then on the Dell iDRAC use the ‘Virtual Media’ menu to ‘Map Removable Disk…’  :… Read more »

Docker jasonrivers/nagios Permissions Problem

I was running this docker image proxied via traefik but I was receiving an error message in the Nagios web interface: docker nagios Error: Could not read object configuration data And in the logs from the container: container_name | Warning: File ‘/opt/nagios/var/perfdata.log’ could not be opened – service performance data will not be written to… Read more »

Determine Dell Hard Disk Location from Linux

On a Dell server I needed to determine the physical hard drive location for a faulty disk. Within the operating system the disk was mounted as /dev/sdk so I ran: udevadm info –query=all –name=/dev/sdk And from the output I could correlate this with the information in the iDRAC: So in this example disk 10 on… Read more »

Dell racadm on Linux

I’m currently using Linux Mint and wanted to communicate with the iDRAC interfaces on Dell servers. Install racadm: sudo echo ‘deb http://linux.dell.com/repo/community/ubuntu xenial openmanage’ | sudo tee -a /etc/apt/sources.list.d/linux.dell.com.sources.list sudo gpg –keyserver pool.sks-keyservers.net –recv-key 1285491434D8786F gpg -a –export 1285491434D8786F | sudo apt-key add – sudo apt-get update sudo apt-get install srvadmin-idracadm8 Test with: /bin/racadm -R… Read more »

Command Line Optimise JPEG image

This command significantly improved file size on disk although the quality value can be increased to adjust the image quality versus file size: convert input-file.jpeg -sampling-factor 4:2:0 -strip -quality 60 -interlace JPEG -colorspace RGB output-file-60.jpeg  

Cropping / Masking a Video for Kdenlive

I was helping a friend with creating a video and we need to mask out the distracting content around the video subject. If I had this problem with a static image I would use Gimp and the ‘Crop’ tool but I couldn’t find anything in Kdenlive to allow me to crop out a small square… Read more »

Managing RDP Remote Desktop Sessions/Users

RDP Session Manager

It took me a little digging to re-discover the name of this tool that allows remotely logging RDP users off from other servers so I thought I would write it down in case I need a reminder. The command to run is: tsadmin.msc Or it can be added directly from the MMC.

Laravel Quick Start

Quick reminder of steps to setup a Laravel project on Ubuntu/Linux Mint and similar. First install composer: sudo apt install composer Install PHP dependencies: sudo apt install php-cli-prompt php-common php-composer-semver php-composer-spdx-licenses php-fpm php-json-schema php-mysql php-symfony-console php-symfony-filesystem php-symfony-finder php-symfony-process php7.0-cli php7.0-common php7.0-fpm php7.0-gd php7.0-json php7.0-mbstring php7.0-mcrypt php7.0-mysql php7.0-opcache php7.0-readline php7.0-xml php7.0-zip php7.0-gd php7.0-mbstring php7.0-mcrypt php7.0-mysql   Use composer to create your Laravel project: composer create-project –prefer-dist laravel/laravel myprojectname Install composer.json packages: composer install Generate a key for your new project into the .env file: php artisan key:generate Amend the .env file with database details and anything else you want to customise. You may want to install mysql with sudo apt install mysql-server Auth Scaffolding… Read more »

Resetting Root Password in Single User Mode

Using Red Hat  / CentOS etc one method of resetting the root user password is to boot into single user mode. To do so, interrupt the booting process if necessary so that you see the Grub boot menu: Press the ‘e‘ keyboard button to edit the boot parameters. You will see a menu with the… Read more »

Password-less Login to the MySQL Command Line

The goal here was to be able to log in to the MySQL command prompt be simply typing mysql rather than: mysql -u root -p This is particularly useful for automation of routine backups etc. mysql_config_editor The command mysql_config_editor has several options (e.g. add, remove, print) for managing encrypted passwords. To create a new login… Read more »