debian

How to enable port 465 (smtps) in postfix mailserver 1

How to enable port 465 (smtps) in postfix mailserver

More and more internet access providers are closing port 25 to reduce spam except for connections to their own mail servers. If you run your own email server and have problems connecting to it on port 25, you can enable port 465 (SMTPS) in postfix as a workaround. Edit the /etc/postfix/master.cf file: nano /etc/postfix/master.cf and …

How to enable port 465 (smtps) in postfix mailserver Read More »

Debugging of ISPConfig 3 server actions in case of a failure

The following article describes the steps that need to be taken to debug ISPConfig 3 server scripts. This procedure applies to all ISPConfig 3 versions incl. ISPConfig 3.1 and ISPConfig 3.2. Enable the debug Loglevel in ISPConfig Login to the ISPConfig interface and set the log level to Debug under System > System > Server …

Debugging of ISPConfig 3 server actions in case of a failure Read More »

Linux Basics: How to view log files on the shell 2

Linux Basics: How to view log files on the shell

Most Linux servers are administered on the command line e.g. through an SSH connection. In the following tutorial, I will explain several shell commands that make it easy to view log files on the Linux command line (shell). These commands will work on all major Linux distributions incl. AlmaLinux, CentOS, Debian, Fedora, RockyLinux, and Ubuntu. …

Linux Basics: How to view log files on the shell Read More »

Get the disk health status with SMART monitor tools on Debian and Ubuntu Linux

Every current disk includes a built-in monitoring feature known as SMART that keeps track of faults. On Linux, there is a software package called smartmontools that may be used to query the SMART status of the disk to see if it will fail soon. Installation apt-get install smartmontools Usage First we need to know the …

Get the disk health status with SMART monitor tools on Debian and Ubuntu Linux Read More »

How to prevent a Linux system user from logging into the system

The shell setting in /etc/passwd determines whether a Linux system user may log in via the shell or over SSH. If you don’t want a certain user to be able to log in, set the shell to /bin/false or /sbin/nologin. For the user “otheruser” on Debian and Ubuntu Linux, here’s an example: usermod -s /bin/false …

How to prevent a Linux system user from logging into the system Read More »

Get a list of all virtual hosts which are defined in all apache configuration files

Have you ever looked in the apache config files to see where a website’s virtual host is defined? The apache2ctl script has a useful option that could come in good here. When you execute the command, it should look like this: apache2ctl -S You’ll obtain a list of all virtual hosts and default servers in …

Get a list of all virtual hosts which are defined in all apache configuration files Read More »

How to download and extract a .deb package on Ubuntu or Debian Linux

Sometimes you require a certain file from a Debian .deb package. For example, because you accidentally deleted a file. Or because the package’s installation is faulty and it can’t be restored without first adding the missing file. This FAQ explains how to extract the contents of a.deb file downloaded from the Debian or Ubuntu repository. …

How to download and extract a .deb package on Ubuntu or Debian Linux Read More »

Get the name of the newest file in a directory on the linux shell

If you have a directory with many files (a few thousand in my case) and need to know which one is the newest, then the following command might be useful. It returns the name and details of the newest file in a directory where it is executed: ls -tl | sed -n 2p The post …

Get the name of the newest file in a directory on the linux shell Read More »

Reduce CPU and Disk load of backup scripts with nice and ionice

Running a nightly backup script on a server system, such as a web hosting server, can result in a heavy load and longer latency for other processes, for example, HTML or .php pages load slowly during the backup because the backup script requires too many I/O or CPU resources. On Linux systems, two shell utilities …

Reduce CPU and Disk load of backup scripts with nice and ionice Read More »