All commands below has to be run as root user. The very first step is to update the Ubuntu package lists:
apt-get update
Then install the SSH server (if you have not installed it already).
apt-get install openssh-server
Installation of mod_pagespeed and Memcached
Installation of mod_pagespeed
Google provides Debian packages for mod_pagespeed for 32 and 64-bit installations.
Debian 64 bit (this should be the right for most current servers)
Mirror across two storage servers
Setting up the GlusterFS Servers
server1.example.com/server2.example.com:
The latest GlusterFS version is available as Ubuntu package from gluster.org. We can install it as follows:
We add the public key of the gluster.org Ubuntu repository on both servers.
wget -O – http://download.gluster.org/pub/gluster/glusterfs/3.7/3.7.9/rsa.pub | apt-key add –
How to configure sudo for two-factor authentication
Configure sudo on Centos/RHEL for two-factor authentication
We will start on RHEL/Centos 7. Install the pre-requisites:
sudo yum -y install make gcc pam pam-devel
Get the latest PAM RADIUS code (1.4 as of this writing):
wget ftp://ftp.freeradius.org/pub/radius/pam_radius-x.x.x.tar.gz
Basic Setup Web Server on Ubuntu 14.04
Step One — Basic Server Setup
Once your server is up and running, there are some standard procedures that you should complete in order to build a good foundation. We call this our initial server setup.
You should go through this guide before continuing, especially steps 1-4. This will show you how to get logged in, create a regular user account, and give that user administrative privileges.
Rsync Command Example
This is an example for copying data from a local server to a remote server (push).
# cd / (starting directory)
# rysnc -avhP local_directory user@1.1.1.1:/remote_directory
-a = archive mode; equals -rlptgoD
-v = verbose
-h = human readable
-P = show progress
How To Set Up an NFS Share on Ubuntu 14.04
Download and Install the Components
You need to install the necessary components on the host server.
# sudo apt-get update
# sudo apt-get install nfs-kernel-server
How To Set Up an NFS Mount on Ubuntu 14.04
Download and Install the Components
You need to install the necessary components on the client server.
# sudo apt-get update
# sudo apt-get install nfs-common
Why Postfix deliver mails locally instead of relaying
This only works if mydomain.com is not the domain configured in Postfix. Because Postfix thinks everything is local when you configured it to be local.
To fix this problem modify Postfix main.cf file:
mydestination = localhost.localdomain, localhost
fallback_transport = relay
BIND DoS vulnerability CVE-2015-5477 – Security fix for in CentOS, RedHat, Debian and Ubuntu Servers
Vulnerability Issue:
A flaw was found in the way BIND handled requests for TKEY DNS resource records. A remote attacker could use this flaw to make named (functioning as an authoritative DNS server or a DNS resolver) exit unexpectedly with an assertion failure via a specially crafted DNS request packet.
