OpenBSD related tutorial/FAQ

How to check disk space on Unix servers

last updated July 26, 2019 in AIX, Commands, FreeBSD, HP-UX Unix, OpenBSD, UNIX

I recently switched from a Windows server 2016 to a FreeBSD Unix server. I need to check disk space on Unix command line. How do I find out disk space utilization information using the Unix command-line option?

OpenBSD install MariaDB database server

last updated January 17, 2019 in MySQL, OpenBSD, UNIX

How do I install MariaDB database servers on OpenBSD Unix operating systems?

How To Set Up SSH Keys on RHEL 8

last updated November 30, 2018 in Cryptography, Linux, OpenBSD, RedHat and Friends

I am a new RHEL 8 server sysadmin. How do I configure SSH public key-based authentication for RHEL (Red Hat Enterprise Linux) 8 server?

Ubuntu 18.04 Setup SSH Public Key Authentication

last updated October 24, 2018 in OpenBSD, Ubuntu Linux

I am a new Ubuntu 18.04 LTS user and I would like to setup ssh public key authentication. How do I set up ssh keys based authentication on Ubuntu Linux 18.04 LTS server? How do I set up SSH keys on an Ubuntu Linux 18.04 LTS server? In Ubuntu 18.04 LTS, how do I set up public key authentication?

Ansible reboot Linux machine or server with playbooks

last updated October 6, 2018 in CentOS, Debian / Ubuntu, FreeBSD, Linux, OpenBSD, RedHat and Friends, Suse, UNIX

I need to reboot the VM or bare metal Linux machine/server using Ansible and wait for it to come back, but it does not work with playbook as descried here. How to reboot Linux server with Ansible? How do I reboot and wait for reboot to complete in Ansible playbook for multiple Linux servers?

Ubuntu Linux install OpenSSH server

last updated August 17, 2018 in OpenBSD, Ubuntu Linux

How do I install OpenSSH server on Ubuntu Linux?

Ping using specific gateway interface or source IP address

last updated July 29, 2018 in FreeBSD, Linux, Networking, OpenBSD, UNIX

I have multiple gateways configured on my Linux or Unix based router. How do I ping through a specific interface of the gateway? How can I ping using a particular source IP address?

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