Category Archives: Linux

Accessing Samba on Manjaro: failed to retrieve share list from server

A few days ago I got my shiny new StarBook Mk V and installed Manjaro on it for the very first time. I have no prior experience neither with Arch-based distros not rolling releases. Anyway, soon after I installed it I realized that I can’t access my homemade NAS server over Samba. I have a samba network at home with a mix of Linux (Linux Mint, Manjaro) and Windows 10 (don’t judge me) computers. Samba has always worked well to connect to each other. But now, when opening smb://192.168.1.6 in Gnome file manager I get this error: Failed to retrieve share list from server: Invalid argument

After quick duckling I found the solution: everything you need to do is to add these two lines in the global section of /etc/samba/smb.conf file on the server

client min protocol = CORE
server min protocol = CORE

and then restart it:

sudo service smbd restart

Voila!

P.S. The solution is based on the original post on the Manjaro forums here.

PHP Warning: PHP Startup: mcrypt: Unable to initialize module

If you have installed multiple PHP versions using PPA maintained by Ondrej Surý you may end up with the following error message:

PHP Warning: PHP Startup: mcrypt: Unable to initialize module
Module compiled with module API=20190902
PHP compiled with module API=20170718

This is caused by a misconfiguration: the php.ini file is pointing to the latest version of mcrypt instead of the one compiled for PHP 7.2. To fix that you have to correct the path to the extension. Open the file for editing:


sudo vi /etc/php/7.2/cli/conf.d/mcrypt.ini

and replace extension=/usr/lib/php/20190902/mcrypt.so with extension=/usr/lib/php/20170718/mcrypt.so. Do the same for /etc/php/7.2/fpm/conf.d/mcrypt.ini file.

If you have the module mcrypt.so listed in /etc/php/7.2/cli/php.ini or /etc/php/7.2/fpm/php.ini – delete it to avoid “PHP Warning: Module ‘mcrypt’ already loaded in Unknown on line 0” error

Install the latest versions of Vagrant and VirtualBox on Linux Mint 19.2

I use Linux Mint 19.2 as daily driver on my ThinkPad L480. This step by step tutorial will guide you through the process of getting the latest versions of VirtualBox and Vagrant instead of the outdated versions available in the official Ubuntu repositories.

VirtualBox and Vagrant receive updates on Linux much often than the repositories update. If you want to consistently get these updates when they become available, you’ll want to add VirtualBox and Vagrant repository to your system. This will allow you to get notified for new versions and update trough Linux Mint Update Manager and apt.

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Batch rename files with Cyrillic filenames to Latin ones (transliterate file names)

If you have a bunch of files with Cyrillic file names, there is a chance that some old devices such as TV embedded players, car audio systems, mp3 players may not recognize them or fail to read. The quick and dirty solution is to rename these files to Latin only characters. In order to save some time I use this handy bash script. It works flawlessly on both Windows (Git Bash) and native Linux systems. Continue reading →

This machine ID is already enabled with a different key or is non-unique

I have purchased new VPS and I wanted to enable Ubuntu live patch service for it. Unfortunately, the command canonical-livepatch enable [TOKEN] failed with this ugly error message:

This machine ID is already enabled with a different key or is non-unique.
Either “sudo canonical-livepatch disable” on the other machine, or regenerate a
unique /etc/machine-id on this machine with
“sudo rm /etc/machine-id /var/lib/dbus/machine-id && sudo systemd-machine-id-setup” :
{“error”: “Conflicting machine-id”}

I thought to myself “Ok, let’s try the suggested solution”. What I did was to backup the file /etc/machine-id, than delete it and run suggested systemd command. I was surprised to see the newly generated UUID was the same! Consulting with man page of systemd-machine-id-setup command revealed that “If run inside a KVM virtual machine and a UUID is configured (via the -uuid option), this UUID is used to initialize the machine ID. The caller must ensure that the UUID passed is sufficiently unique and is different for every booted instance of the VM.”. Obviously, my new VPS provider did not ensure that and somebody else has the same machine ID on his/her VPS and enabled Ubuntu live patch for it.

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Vagrant: Authentication failure. Retrying…

I recently bought a newer laptop. It had Windows 8 preinstalled which I wiped immediately in order to install Linux Mint 19.1 and started to migrate data from my old machine. I packaged my vagrant box and transferred it to the new machine. Once imported the box back and issued vagrant up command I was surprised by the following errors:

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Control screen backlight brightness from the command line

I have a Dell Latitude E5430 running Linux Mint 19 Tara. In Cinnamon, my function keys for brightness work correctly, but that was not the case with i3wm session. My first bet was to bind shortcuts executing xbacklight command but it doesn’t work because of this bug. So, I started to research for workaround and I found brightlight – “a program that can get and
set the screen backlight brightness on Linux systems using the kernel sysfs
interface.”. Sounds perfect but there are no prebuild binaries so you need to do it by yourself. The following steps are short guide how to build and install brightlight on Ubuntu and Ubuntu derivatives.

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How to install PHP Data Structures (DS) extension on Ubuntu 16.04

First, you will need to install PEAR via apt-get to get the necessary package and distribution system that both PEAR and PECL use. From a shell prompt enter:

sudo apt-get install php-pear

You will be prompted to confirm the install. Just press “y” and enter. If all goes well you should see it download and install the php-pear package.

Now you will need to install the php-dev package to get the necessary PHP7 source files to compile additional modules. Enter the following from a shell prompt:

sudo apt-get install php-dev

If you do not install the php-dev package and try to install a PECL extension using “pear install”, you will get the following error:

sh: phpize: not found
ERROR: `phpize’ failed

The PECL_HTTP extension requires an additional dependency package to be installed. You can probably skip this for other extensions:

sudo apt-get install libcurl4-openssl-dev

Now we are finally ready to actually install the extension. From a shell prompt enter following:

sudo pecl install ds

The installer may ask you about some specific options for the extension you are installing.  Just accept the defaults and go ahead.

Once the install is complete, it’s time to enable the extension.
First, edit the following file (create it if it does not exist already):

sudo vi /etc/php/7.0/mods-available/ds.ini

and change it’s contents to:


; configuration for php ds module
; priority=30
extension=ds.so

Than check and remove any symbolic links to 20-ds.ini file, such as:

sudo rm /etc/php/7.0/fpm/conf.d/20-ds.ini
sudo rm /etc/php7.0/apache2/conf.d/20-ds.ini
sudo rm /etc/php7.0/cli/conf.d/20-ds.ini

You need to remove above listed symlinks because of bug: there is hard dependency on the json extension. DS extension shouldn’t try to implement JsonSerializable if the json extension is not loaded, but actually do it and it will complain with exception if it is not found:


PHP Warning:  PHP Startup: Unable to load dynamic library '/usr/lib/php/20151012/ds.so'
 - /usr/lib/php/20151012/ds.so: undefined symbol: php_json_serializable_ce in Unknown on line 0

That’s why we removed 20-ds.ini symlinks and specified ds.so to load after json is already enabled.

Now, disable and then re-enable the extension:

sudo phpdismod ds
sudo phpenmod ds

You may need to restart your HTTP server:

# If you are on apache
sudo service apache2 restart
# if you are on nginx
sudo service nginx restart

How to setup Pure-FTPd server on OpenWRT enabled router

I am proud owner of TP-Link TL-WDR3500 router flashed with OpenWRT, which is really good custom firmware offering countless possibilities. Recently I’ve installed FTP server on it so I can access the attached external HDD drive remotely. This how-to is simple guide showing you to configure Pure-FTPd with TLS support on your OpenWRT enabled router, too.

Why Pure-FTPd

There are many reasons to prefer Pure-FTPd over other FTP servers available as OpenWRT packages:

  • It is a secure FTP server
  • It has FTPS support (offers optional TLS Encryption)
  • You can use both real user accounts and virtual ones
  • You can put every user in a chroot jail

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How to install mailcatcher on CentOS 7 and configure it for PHP

The problem

Handling outgoing emails in a web application can be hard, because it’s very easy things to get wrong and send unwanted test mails to real world customers while testing some functionality.
Ensuring sent emails are designed, parsed and formatted correctly is a painstaking problem, too.

… and the solution

Mailcatcher is a program you can use to test sending email. It gives you the ability to inspect sent emails and their headers. It is a simple SMTP server that can receive emails. It also gives you a nice web interface to preview the sent emails.

We’ll cover installing the dependencies for Mailcatcher. Then we’ll install and set it up for easy use in our development environment. This includes use with PHP. Finally, we will setup password protect subdomain for easier access using Nginx.

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