AllSupported - Tech Support & Tutorials

How to Fix Permission Denied Errors in Linux: Complete Guide

Mon, 01 Dec 2025 15:43:43 -0500

Learn how to troubleshoot and fix Permission Denied errors in Linux with chmod, chown, and proper file permissions. Includes solutions for SSH keys, scripts, and web servers.

How to Fix No Space Left on Device Errors in Linux

Mon, 01 Dec 2025 15:43:43 -0500

Complete guide to diagnosing and fixing disk space issues in Linux. Learn how to find large files, clean up logs, and free up space safely.

Troubleshooting Network Connectivity Issues in Linux: Complete Guide

Mon, 01 Dec 2025 15:43:43 -0500

Learn how to diagnose and fix network problems in Linux. Covers ping, traceroute, DNS issues, firewall problems, and interface configuration.

Systemd Service Troubleshooting: Complete Guide to Fix Failed Services

Mon, 01 Dec 2025 15:43:43 -0500

Master systemd troubleshooting with this comprehensive guide. Learn how to diagnose failed services, read logs, and fix common systemd issues in Linux.

Fix SSH Connection Refused and Timeout Errors in Linux

Mon, 01 Dec 2025 15:43:43 -0500

Complete guide to troubleshooting SSH connection problems. Learn how to fix connection refused, timeout, and authentication errors.

How to Fix APT Package Manager Errors in Ubuntu and Debian

Mon, 01 Dec 2025 15:43:43 -0500

Solve common apt-get and apt errors in Ubuntu/Debian. Fix broken packages, lock files, dependency issues, and repository problems.

Linux Performance Monitoring: Find High CPU and Memory Usage

Mon, 01 Dec 2025 15:42:13 -0500

Master Linux performance monitoring with top, htop, ps, and other tools. Learn how to identify and kill processes causing high CPU and memory usage.

Turn off laptop display when HDMI is plugged-in (external display primacy)

Sun, 15 Sep 2024 10:19:11 -0400

Running on the the display that is needed will save power, reduce thermal load on your laptop heat pipes and fans. This will also conserve the battery and extend the life of your display if it's only

Debian Fix missing GPG NO_PUBKEY key

Thu, 04 Apr 2024 18:08:42 -0400

If you get an error like this "The following signatures couldn't be verified because the public key is not available: NO_PUBKEY" Fix with this command: apt-get install debian-keyring debian-

Create 100GB swap file in one line

Thu, 08 Apr 2021 00:12:42 -0400

Create 100GB swap file in Linux using a single line. The file will be named swapfile1. dd if=/dev/zero of=/swapfile1 bs=1024 count=104857600 && chown root:root /swapfile1 && chm

Fix "Row size too large (> 8126). Changing some columns to TEXT or BLOB or using ROW_FORMAT=DYNAMIC or ROW_FORMAT=COMPRESSED may help. In current row format, BLOB"

Thu, 25 Mar 2021 00:59:35 -0400

One possible solution is to simply add this line before your SQL query to get around this issue. SET SESSION innodb_strict_mode=OFF; https://jira.mariadb.org/browse/MDEV-10364

Installing new Kernels with Linux

Mon, 15 Feb 2021 10:47:19 -0500

Here's a simple tool to facilitate the installation of mainline Kernels. https://github.com/bkw777/mainline

Resolve Debian, Ubuntu slow DNS lookups

Sun, 18 Oct 2020 01:50:04 -0400

This issue can be caused by many things however if you are using a recent version of linux you may want to try to the following links. Diagnostics of the issue https://www.math.tamu.edu

Install Imagick with PHP 7.4 Debian

Sun, 18 Oct 2020 00:27:18 -0400

Follow this guide https://www.tecmint.com/install-imagemagick-on-debian-ubuntu/

PHP 7.4 on Debian for Servers

Sat, 17 Oct 2020 21:36:15 -0400

For Debian servers already stripped of sudo. apt install -y apt-transport-https lsb-release ca-certificates wget wget -O /etc/apt/trusted.gpg.d/php.gpg https://packages.sury.org/php/apt.gp

Resolve 'ERROR: '/usr/sbin/iptables-restore -w -n' failed: iptables-restore v1.8.2 (nf_tables):'

Sun, 11 Oct 2020 20:51:01 -0400

After changing the configuration of a firewall the journal may report an error when restarting the firewall service such as the following: ERROR: '/usr/sbin/iptables-restore -w -n' failed: iptables-r

VirtualBox error "same UUID as an existing virtual machine."

Sun, 11 Oct 2020 13:45:50 -0400

If you copy a VirtualMachine without using the Clone command in VirtualBox you might receive an error similar to Trying to open a VM .. which has the same UUID as an existing virtual machine. The way

Shrink VirtualBox Disk Ubuntu

Thu, 09 Apr 2020 14:51:20 -0400

In order to recover diskspace on your VirtualBox host machine it is necessary to zero out the unused portion of VirtualBox disks. Follow these steps to get the job done. install zerofree s

Linux Security OS and Default Passwords

Sun, 22 Mar 2020 16:57:08 -0400

Parrot OS User: root Password: toor Homepage: https://parrotlinux.org/ Download: https://parrotlinux.org/download.php BlackArch Linux User: root Password: blackarch Homepage: https://blackarch.org/

How to stop black screen flickering NVidia, Ubuntu, Cinnamon, Mint

Thu, 12 Mar 2020 15:53:13 -0400

This will work on Linux Mint 18, Linux Mint 19, Ubuntu, Ubuntu with Cinnamon Desktop Environment and other Linux systems using the NVidia drivers. Open your application menu Search "nvidia"

Remove all games in Ubuntu and Debian in one line

Tue, 03 Mar 2020 16:58:20 -0500

The default installation of popular Debian-based desktop operating systems include many games. For developers and diskspace conscious users these games are unessary. To remove all the games using a

How to fix: You do not have permissions necessary to view the contents of "sf_Shared"

Mon, 02 Mar 2020 12:42:51 -0500

When attemping to add shared folder from a Host machine to a Guest VirtualBox machine you may encounter the following error. This location could not be displayed. "You do not have permissions necessa

Disable Blueooth Gigabyte Ryzen Linux

Mon, 02 Mar 2020 02:22:22 -0500

For optimal security we will disable Bluetooth when Linux is starting up. We will add the following command in /etc/rc.local rfkill block bluetooth Since as of Ubuntu 18.04 there is no longer

Access/Copy Android Files using Ubuntu / Linux / Debian

Wed, 05 Feb 2020 22:43:40 -0500

Ensure you're using the original cable for data transfer. Some USB cables will not work correctly for data transfer. Afterwards install the necessary packages as indicated below. Access/Copy Android

Disable Cinnamon 2D rendering alert

Mon, 13 Jan 2020 02:32:30 -0500

echo "export CINNAMON_2D=true" >> ~/.profile Credits: https://unix.stackexchange.com/questions/295921/how-do-i-turn-off-the-running-in-software-rendering-mode-warning

Fix file permissions

Mon, 21 Oct 2019 04:58:32 -0400

Synching files and copying files between devices can sometimes lead to incorrect permissions. Use the following lines to set them back to your desired permission based on their type, either Files [-t

Meteor Reactive Joins

Tue, 08 Oct 2019 18:58:41 -0400

https://www.discovermeteor.com/blog/reactive-joins-in-meteor/ Use this package https://github.com/peerlibrary/meteor-reactive-publish Meteor.publish('subscribed-posts', function () { this.autorun(

NVM 'You need to run "nvm install N/A"'

Tue, 08 Oct 2019 18:49:25 -0400

If you've changed node versions with NVM you might experience this error message in the console. N/A: version "N/A" is not yet installed. You need to run "nvm install N/A" to install it before using

Fix Firefox force HTTPS redirects on development machines

Mon, 20 May 2019 10:37:38 -0400

This stackoverflow explains the issue and provides good solution to this annoying problem. First clear Site Preferences then, Look for network.stricttransportsecurity.preloadlist and set it to "false

Install and configure PHP + NGINX for Ubuntu 18.04

Mon, 13 May 2019 23:14:22 -0400

How to install and configuration NGINX with PHP. It's really simple. Install NGINX and php-fpm apt install nginx php-fpm Then add this configuration to the NGINX site with which you want to enable P

Meteor get Collections by Reference

Tue, 23 Apr 2019 16:53:53 -0400

This short code sample will show you how to get access to a Collection by reference. The root variable is essentially referencing the this global but detects the correct global reference based on

Iron Router Multiple Data Context with Meteor

Tue, 23 Apr 2019 13:30:49 -0400

Here's how to do it: Router.route('/things', { name: 'things', waitOn: function () { return [this.subscribe('thing'),this.subscribe('thinga')]; }, data: function () {

Set Fn key to always on with Apple keyboard

Mon, 08 Apr 2019 21:24:37 -0400

If you're using an Apple keyboard with Linux and want to use the Function keys normally, for example F2 to rename files, it's possible to do so with a simple modification. Open a terminal and run thi

How to create a telephone number link that opens dialer on mobile devices?

Sat, 06 Apr 2019 20:00:23 -0400

HTML5 has some nice new tricks. One of them is creating dialable links and here's how: 111-222-3333 That's right. It's as simple as that!

How to Fix Ubuntu Landscape - Invalid Machine token

Wed, 03 Apr 2019 17:16:21 -0400

Ubuntu Landscape allows you to keep systems updated when deployed in large clusters. If you clone a machine and look in its logs you might find an error message similar to the ones below. Error mess

Fix slow GUI, sluggish interface with Mint Cinnamon

Wed, 03 Apr 2019 15:09:40 -0400

If you have been using your system heavily, with multiple workspaces, various applications that are not entirely memory efficient, these combined factors can lead to your interface feeling slu

Monitor Postfix mail Queue

Wed, 13 Mar 2019 14:08:46 -0400

watch -n1 mailq Credits: https://www.techbrown.com/monitor-postfix-mail-server-ubuntu-16-04/

Continuous network monitoring with linux

Tue, 12 Mar 2019 13:30:53 -0400

For displaying network activity continuously in Linux via the command line. CLI netstat -t -u -c

SSH Tunneling on Linux and Mac

Tue, 12 Mar 2019 01:03:34 -0400

Do you need to tunnel to another machine frequently? Would you like an App to save time and make it more user friendly? Well, good news! There's a solution for Linux and Apple machines. For Linux

Debian Unattended Security Updates

Tue, 11 Dec 2018 23:26:29 -0500

Follow these instructions and set your email to receive notifications. https://wiki.debian.org/UnattendedUpgrades apt-get install unattended-upgrades apt-listchanges apticron -y nano /etc/apt/apt.c

Solve Proxmox CloudLinux Kernel Care GPG Error

Fri, 24 Aug 2018 18:49:45 -0400

apt-key adv --keyserver subkeys.pgp.net --recv-key E58FE9B3FE3B0470525159BD6DC3D600CDEF74BB apt-get install dirmngr UPDATE: This issue may be caused by a buggy package installation script

Meteor template instance data context

Sat, 18 Aug 2018 16:03:46 -0400

Working with Meteor templates one must understand how to access data context in the various sections of templates. These links provide good explanations: https://stackoverflow.com/questions/

Proxmox disable swap unless totally out of RAM

Tue, 14 Aug 2018 23:41:09 -0400

The defautl vm.swappiness value for Proxmox 5.2.x is 60 Run this command in Shell in order to reduce swappiness to an absolute necessity when the system is out of RAM. sysctl -w vm.swappines

The public key is not available: NO_PUBKEY 68818C72E52529D4

Sat, 11 Aug 2018 18:54:19 -0400

After adding a mongodb you may experience an error about the GPG PUB KEY like teh following. W: GPG error: http://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/testing Release: The following signatu

Meteor Remote MongoDB

Fri, 10 Aug 2018 14:27:13 -0400

I don't like to use big repeating command and I was searching for a solution where I will be setting a variable embedded with something so every time I start my meteor app; the MONGO_URL will set to e

Meteor-up, LXD, Proxmox

Fri, 10 Aug 2018 00:00:16 -0400

When trying to setup a meteor up node on proxmox CT the console will give out this error. failed to register layer: ApplyLayer exit status 1 stdout: stderr: permission denied This is because a

Fix: Error: Cannot find module '@babel/runtime/helpers/builtin/objectSpread'

Thu, 09 Aug 2018 23:03:36 -0400

Another common error: Error: Cannot find module '@babel/runtime/helpers/builtin/interopRequireDefault' How to fix: This has been traced in the forums as an incompatibility with the latest versio

Proxmox XFCE4 Setup with Ubuntu + VNC Server

Sat, 04 Aug 2018 02:17:19 -0400

Configure your instance using this guide to install the necessary packages and setup VNC to start on reboot. Tip: You will want to connect via SSH tunnel to your VNC server. That is the safest way to

Fix Gitlab won't start, database system is shut down, failed to load.

Sat, 23 Jun 2018 14:55:27 -0400

When you have issues with GitLab you will want to check the status to see which component of gitlab is not working as expected. Do this using the following command: sudo gitlab-ctl status Verify the l

Fix Discord App Black Screen Crash Virtualbox

Wed, 02 May 2018 12:32:47 -0400

Windows, Linux (Ubuntu, Mint, Debian etc...), MacOS may be affected by this issue if you are using running a guest operating system and trying to use Discord. In order to resolve this issue follow th