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Linux Security

SOLVED: Error apt update – NO_PUBKEY 78BD65473CB3BD13

If after the linux apt update command you receive an error about NO_PUBKEY, similar to what is seen below: root@epyc:~# apt update Hit:1 http://de.archive.ubuntu.com/ubuntu focal InRelease Hit:2 http://ppa.launchpad.net/ondrej/php/ubuntu focal InRelease Get:3 http://security.ubuntu.com/ubuntu focal-security InRelease [114 kB] Get:4 http://de.archive.ubuntu.com/ubuntu focal-updates InRelease [114 kB] Ign:5 http://dl.google.com/linux/mod-pagespeed/deb stable InRelease Get:6 http://dl.google.com/linux/mod-pagespeed/deb stable Release [2154 B] Get:7 http://dl.google.com/linux/mod-pagespeed/deb stable Release.gpg […]

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Linux Security Useful

SOLOVED: signatures were invalid EXPKEYSIG 97BD1A0133449C3D Gerardo Orellana

If after the linux apt update command you receive an error similar to what is seen below: root@epyc:~# apt update Get:1 http://security.ubuntu.com/ubuntu focal-security InRelease [114 kB] Ign:2 http://dl.google.com/linux/mod-pagespeed/deb stable InRelease Hit:3 http://ppa.launchpad.net/ondrej/php/ubuntu focal InRelease Get:4 http://dl.google.com/linux/mod-pagespeed/deb stable Release [2154 B] Hit:5 http://de.archive.ubuntu.com/ubuntu focal InRelease Get:6 http://dl.google.com/linux/mod-pagespeed/deb stable Release.gpg [819 B] Get:7 http://de.archive.ubuntu.com/ubuntu focal-updates InRelease [114 […]

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Linux Servers

Fixing kernel error AMD-Vi IO_PAGE_FAULT – Linux

Without any clear reason, today an error appeared on my home server, in fact the server crashed and did not respond to any commands, the only option was the hardware reset, from the button! The server is a HTPC, with remote access (headless server), based on a Ryzen 2400G processor, 16GB Ram, 1xNVMe, 1xSSD, 4xHDDs […]

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Linux Useful

Hot to find your Linux Kernel Version

Below are the usual 4 Commands to Find Linux Kernel Version uname uname -r # find Linux kernel version uname -a # for all information related to kernel version, lsb_release lsb_release -r # for the exact version lsb_release -a # for all information related to the Ubuntu version, lsb_release -sr # distribution version number: proc/version cat /proc/version # details about for […]

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Linux Servers Useful

How to Update Linux Kernel to 5.5.0

To upgrade to linux 5.5.0 kernel, you can perform the following steps: 1st) Download the following files to an empty folder (for 64bit & generic kernel): wget https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.5/linux-headers-5.5.0-050500_5.5.0-050500.202001262030_all.deb wget https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.5/linux-headers-5.5.0-050500-generic_5.5.0-050500.202001262030_amd64.deb wget https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.5/linux-image-unsigned-5.5.0-050500-generic_5.5.0-050500.202001262030_amd64.deb wget https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.5/linux-modules-5.5.0-050500-generic_5.5.0-050500.202001262030_amd64.deb 2nd) execute the command: sudo dpkg -i *.deb 3rd) In the end, after the installation has taken place, all you have […]

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Linux Servers

Stop Random Standy/Sleep in Ubuntu-Linux Server

My Ubuntu Server 18.04, is without a monitor / keyboard connected (headless server) and has been running for several years, but today I updated to the latest kernel version because I couldn’t find the solution to a problem that suddenly appeared and without any apparent cause: AMD-Vi IO_PAGE_FAULT error. From what I found online, it […]

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Linux Useful

Automatic REBOOT if needed after apt-get upgrade – Linux

Sometimes after the execution of the apt-get upgrade command is finished, a restart is required, but this is not displayed after the command is completed, but you have to do it manually. To do this, you need to check the existence of the /var/run/reboot-required file and then restart the system if the file exists. To […]

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Linux Useful

Change the extension of multiple files in Linux

1). Using Linux find command Using find command to rename all .oldext files under directory structure with a new extension: .newext find . -type f -name “*.oldext” -exec rename ‘s/\.oldext$/.newext/’ ‘{}’ \; 2). Using Linux find command, but in a different approach for f in `find . -iname ‘*.oldext’ -type f -print`;do mv “$f” ${f%.oldext}.newext; […]

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Linux Useful

du – Get the Size of a Folder in Ubuntu Linux

The linux du command displays the size of file space used by the specified files or folders. If the specified path is a directory (folder), du summarizes disk usage of each subdirectory in that directory. Otherwise, du reports the disk usage of the current working folder. To get the total size of the /srv folder, […]

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Linux Security Servers

Install OpenVPN, DNSCrypt and Pi-Hole – Ubuntu 20

Step by step: Install OpenVPN + Pi-Hole ad-blocker + DNSCrypt-proxy for DoH and DNSSEC Step 1. Update the system: sudo apt update sudo apt upgrade Step 2. Install OpenVPN: wget https://git.io/vpn -O openvpn-install.sh chmod 755 openvpn-install.sh sudo ./openvpn-install.sh Generated opvn file can be used with an OpenVPN client in PC or cell phone. It can be […]