Change grub default boot option on Linux Ubuntu/Mint

Grub's default boot option is stored within a config file found on the partition where your Master Boot Record is located (if you had it installed previously, there may also be grub.cfg files on other partitions, but these won't affect boot sequence). Its direct path is /boot/grub/grub.cfg and it has to be opened as root, ... Read more

How to Disable quota for a Linux User or Group on the Shell

Linux user quotas can be edited with the commands edquota or setquota on the shell. While edquota opens the quota settings in an editor like vim, setquota allows you to specify the quota settings on the command line. Example for disabling the quota for the user "testuser": setquota -u testuser 0 0 0 0 -a ... Read more

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 ... Read more

How to Build and Install OpenSSL from Source on Ubuntu Linux

OpenSSL Cryptography and SSL/TLS Toolkit is an open-source, full-featured package used in Transport Layer Security (TLS) and Secure Socket Layer (SSL) protocols to provide secure communication between client and server. This commercial-grade and robust toolkit is widely used by various programs like PHP, Internet servers, comprising the majority of HTTPS websites. Most Linux distributions come ... Read more