Posts By: jonny

Tab Separated File Returns Wrong Number of Fields

Shell

So we had a CSV/TSV file with tabs separating each field but one of the fields was a description field that contained spaces. When parsing this TSV file some programs interpreted the spaces as field delimiters (TSV might be a bad idea!). Input file similar to: NULL NULL 7.0 Huayang Time Warner Cable 4430 The… Read more »

Install Python Linters in Atom

I installed the relevant Python packages first e.g. sudo apt-get install flake8 python3-flake8 python3-pep8 python-pep8-naming python3-setuptools pylint3 Then on the Atom menu use: Edit > Preferences then search for atom packages such as flake8, pep8, pep257 and pylint: Then click the install button. After restarting style advice is shown in the editor:    

Manic Miner on Linux

I was reminded about how much time I had spent as a kid playing Manic Miner on an Amstrad 464 and decided to give it a try on my current desktop (Linux Mint) so for future reference… I grabbed the code created by here: git clone https://github.com/lkundrak/manicminer.git Installed a few dependencies: apt-get install libx11-dev libxext-dev… Read more »

MySQL Percona Slave Replication Change Channel Name

I had inadvertently set up slave replication using the wrong channel name – which is a minor issue except that it caused some issues with an already configured Nagios check. To ‘change’ the channel name I stopped the slave process, removed all the slave definitions and used ‘CHANGE MASTER’ to re-create the slave from the… Read more »

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