Category Archives: Linux

Solution “Internal Server Error” when opening Nextcloud

Recently moved Nextcloud from one server to another and when it opened, noticed the following error in the browser:

Internal Server Error

The server encountered an internal error and was unable to complete your request.
Please contact the server administrator if this error reappears multiple times, please include the technical details below in your report.
More details can be found in the server log.

In my case, the error occurred because of a damaged MySQL database, so I restored it from another backup and Nextcloud opened.
I assume that the same error can occur when the Nextcloud database exists, but is empty.

See my article:
Install Nextcloud in Ubuntu

Installing Webmin

Webmin – a graphical web interface for managing a Linux server, written in Perl.
Official site: www.webmin.com

Here is an example of installing Webmin in Ubuntu.

Open the list of sources in a text editor:

nano /etc/apt/sources.list

Add this line to it:

deb http://download.webmin.com/download/repository sarge contrib
deb http://webmin.mirror.somersettechsolutions.co.uk/repository sarge contrib

We go to the temporary directory and import the key:

cd /tmp
wget http://www.webmin.com/jcameron-key.asc
apt-key add jcameron-key.asc

We update the list of sources:

apt-get update

We install the packages necessary for the correct operation of Webmin:

sudo apt-get install perl libnet-ssleay-perl openssl libauthen-pam-perl libpam-runtime libio-pty-perl libmd5-perl

Install Webmin:

apt-get install webmin

The installation is complete, to open the Webmin interface we will open in the browser https://HOST:10000

Transfer /boot from a separate partition to a main partition

On the test, I installed a clean Ubuntu Server 18.04, during the installation, the system automatically split the disk into one main /dev/sda1, which already had /boot files.
Since I did not have a system with /boot on a separate partition, I transferred it to a separate one and described the process in this article – Transfer /boot from a main partition to a separate partition

Now let’s move the /boot partition to the main /.

Let’s look at the information about the disks:

sudo fdisk -l
df -h

Continue reading “Transfer /boot from a separate partition to a main partition”

Transfer /boot from a main partition to a separate partition

Today, I’ll give an example of moving /boot from a shared partition to a separate partition.
For the test, you can connect a new disk or use the first partition on any disk, for example, with a size of 512MB.

Let’s look at the information about the disks:

sudo fdisk -l
sudo ls -l /boot
sudo du -hs /boot

Continue reading “Transfer /boot from a main partition to a separate partition”

Upgrading PHP Version on Ubuntu 14.04

Once it was necessary to upgrade the version of PHP 5.5.9 to 5.6 on Ubuntu Server 14.04 LTS, the usual update of the system components did not help:

sudo apt-get update
sudo apt-get upgrade

You can try to upgrade the system to 16.04 or higher as I described in the article Updating Ubuntu 14.04 to 16.04. Together with the system will be updated and PHP.

If the system update fails, you can add a third-party source with PHP:

sudo add-apt-repository ppa:ondrej/php
sudo apt-get update

And install the correct version from it, for example PHP 5.6:

sudo apt-get install php5.6 php5.6-mbstring php5.6-mcrypt php5.6-mysql php5.6-xml

Since there are several installed versions, disable the old version and activate the installed one:

sudo a2dismod php5
sudo a2enmod php5.6
sudo service apache2 restart

Similarly, you can install PHP 7.2:

sudo apt-get install php7.2
sudo a2dismod php5.6
sudo a2enmod php7.2
sudo service apache2 restart

Or PHP 7.0:

sudo apt-get install php7.0
sudo a2dismod php7.2
sudo a2enmod php7.0
sudo service apache2 restart

Let’s Encrypt Plugin in cPanel

To use Let’s Encrypt in cPanel, you need to install a special plugin.
To do this, connect to the server by SSH and execute the command from the root user:

/scripts/install_lets_encrypt_autossl_provider

After installing the Let’s Encrypt plug-in, you can use it in the AutoSSL management menu (WHM >> Home >> SSL/TLS >> Manage AutoSSL).

If you need to remove the plugin, then run the command:

/usr/local/cpanel/scripts/uninstall_lets_encrypt_autossl_provider

See also:
Установка Certbot в Ubuntu

Installing OpenLDAP Server on Ubuntu

Install the necessary packages:

sudo apt-get install slapd ldap-utils

During the installation, you will be prompted for a password for the admin user.

Reconfigure the slapd package:

sudo dpkg-reconfigure slapd

We will test the LDAP connection (should display “anonymous”):

ldapwhoami -H ldap:// -x

To manage LDAP, set up the web interface phpLDAPadmin:

sudo apt-get install phpldapadmin

To open the web interface phpLDAPadmin, type in the browser http://example.com/phpldapadmin, where instead of example.com, specify your domain.
On the opened page we will enter the password which was specified at installation, and where the login:

cn=admin,dc=example,dc=com

Restart example:

sudo /etc/init.d/slapd start