Posts By: jonny

Commenting out multiple lines in vim

To add hashes to multiple lines:

to enter visual mode Arrow Keys to highlight the lines to be changed Inserting: Use one of the following to insert hashes depending on the version of vim

, then the ‘

’ key, then ‘

Deleting: Use the ‘

’ keyboard key  

rpcbind.socket failed to listen on sockets: Address family not supported by protocol

Using CentOS 7 this problem arose after a reboot and NFS shares would not mount. Trying to start the rpcbind service:

gave the following error message via jounralctl -xe :

So it looks like

was set in /etc/sysctl.conf But this wasn’t yet incorporated into the initramfs. Solution Rebuild the initramfs with:

Read more »

Mount Files Virtually via Dell iDRAC

Use fallocate to create a new 300 MB file :

Create an ext4 file system within the image file:

Create a mount point:

mount it:

Then on the Dell iDRAC use the ‘Virtual Media’ menu to ‘Map Removable Disk…’  : Then on the host operating system the device can be mounted… 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:

To solve the issue I connected to the container:

And set the nagios user as the… 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:

And from the output I could correlate this with the information in the iDRAC: So in this example disk 10 on the backplane.  

Dell racadm on Linux

I’m currently using Linux Mint and wanted to communicate with the iDRAC interfaces on Dell servers. Install racadm:

Test with:

or if you want to be prompted for login credentials use:

Example racadm commands Dump lots of info:

Get the status of the PERC/Raid battery:

Set… 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:

 

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:

Install PHP dependencies:

  Use composer to create your Laravel project:

Install composer.json packages:

Generate a key for your new project into the .env file:

Amend the .env file with database details and anything else you want to customise. You may want to install mysql with

Auth Scaffolding Create the login and… Read more »