Archives for Linux Sysadmin Tutorials

How to retrieve the SHA1 fingerprint of a remote server certificate using OpenSSL

Run salt in masterless mode

Configure the I2p i2ptunnel HTTP proxy to listen on all interfaces

Configure the I2P web console to listen on all interfaces

Delete lease from dnsmasq

A quick intro to background and foreground command control in bash.

Correct the file tool from reporting the mime-type of a Python script as text/x-java

Setup sudo with google-authenticator for 2 Factor authentication on CentOS 7.

Use overlayfs as the storage driver in docker on CentOS 7.1

Install and configure php5 fpm to run under a system user account using nginx as the web server on Ubuntu Trusty 14.04.

Configure dnsmasq to query different nameservers for different domains

Specify a different nameserver in /etc/resolv.conf when using DHCP in CentOS

Specify a different nameserver in /etc/resolv.conf when using DHCP in CentOS/RHEL/Fedora

Setup PAM authentication with OpenVPN's auth-pam module

Update the timezone in CentOS 6

Build and install vim 7.4 on CentOS 6 using RPM

Using SIP over TCP with asterisk

Discover Googles Netblocks

Ignore host keys when connecting to an OpenSSH server

Using the appropriate IP networks within Documentation, Diagrams and Example Code

Disable the MOTD from displaying when logging into an Ubuntu server over SSH

Fixing errno 1449 MySQL slave replication error

Setup Nagios NRPE to monitor system load on CentOS

Configure guest domain memory usage with virsh

Find out what commit belongs to what branch in git

Install Nagios on CentOS and monitor a server

How to download RPMs without installing them using yum.

Use boxcar to send nagios alerts

Enable EPEL on a CentOS/RHEL 6 server

Compressing mylvmbackups using xz

Extract PEM certificates and keys from a shared NSS DB

Multiple SSH client configuration files

Transfer a text file over a TCP socket using perl

Create a Maildir directory and its sub directories

Setup postfix to deliver using Maildir

How to sniff MySQL traffic on a database server

Install puppet syntax highlighting for vim

Change the passphrase on an OpenVPN key

Disable UNIStim in asterisk

Setup OpenVPN with Bridging Support on Ubuntu

Install puppetlabs apt puppet module

How to check the expiry of a HTTP SSL certificate on the command line with openssl?

Backup a MySQL database on an Ubuntu server with mylvmbackup.

Edit the default User ID (UID) values for new users

how do I sniff each packet on the command line?

Query a remote NTP server using ntpdate

Create a socks5 tunnel on port 3333 over SSH

Convert InnoDB to InnoDB plugin, compressed tables

Display overhead of all tables in a MySQL database

Handle apt configuration with puppet

Analyse MySQL binary logs with mysqlsla

Strip white space, dash and colons from a date string

Handle apt keys with puppet

Manage apt sources.list with puppet

How to calculate dates in bash

Converting mutt aliases to ldif

Configure openssh to tunnel through another server using SSH

Convert an Outlook PST file to mbox

Create a simple puppet class to maintain sshd