Introduction
NFS, or Network File System, is a distributed filesystem protocol that allows you to mount remote directories on your server. This allows you to leverage storage space in a different location and to write to the same space from multiple servers easily. NFS works well for directories that will have to be accessed...
Thursday, October 8, 2015
Thursday, August 27, 2015
Munin Plugins for MongoDB
Plugins
mongo_ops : operations/second
mongo_mem : mapped, virtual and resident memory usage
mongo_btree : btree access/misses/etc...
mongo_conn : current connections
mongo_lock : write lock info
mongo_docs : number of documents...
Adding Apache Reporting To Munin
When you first install a Munin node it will try to install as many plugins as it can so that it can report on different things. For example, if you have a Varnish server running then Munin will detect this and enable the plugins...
Monday, August 24, 2015
PHP 5.5 on CentOS/RHEL 7.1, 6.7 and 5.11 via Yum
PHP 5.5.28 has been released on PHP.net on 6th August 2015, and is also available for CentOS/RHEL 5.11, 6.7 and 7.1 at Webtatic via Yum.
PHP 5.5 adds new features such a...
Thursday, August 20, 2015
How To Install and Configure Config Server Firewall (CSF) on Ubuntu
Introduction
Config Server Firewall (or CSF) is a free and advanced firewall for most Linux distributions and Linux based VPS. In addition to the basic functionality of a firewall – filtering packets – CSF includes other security features, such as login/intrusion/flood detections. CSF includes UI integration for cPanel, DirectAdmin...
Setup ConfigServer Security and Firewall (CSF) on CentOS 7
ConfigServer Security & Firewall (CSF) is a stateful packet inspection firewall (SPI), login/intrusion detection, and security application for Linux servers. It is a very popular security suite, but isn't officially...
Monday, August 10, 2015
How to Backup and Restore MongoDB using mongodump and mongorestore
mongodump is an useful tool to backup Mongo database. Apart from taking a cold backup, it can also take hot backup. i.e You can connect to a running instance of MongoDB and take a backup even when users are using the database.
mongorestore is an useful tool to restore the MongoDB backup that was taken using mongodump utility.This...
Sunday, July 5, 2015
How To Install an SSL Certificate from a Commercial Certificate Authority
Introduction
This tutorial will show you how to acquire and install an SSL certificate from a trusted, commercial Certificate Authority (CA). SSL certificates allow web servers to encrypt their traffic, and also offer a...
How To Set Up an OpenVPN Server on Ubuntu 14.04
Introduction
Want to access the Internet safely and securely from your smartphone or laptop when connected to an untrusted network such as the WiFi of a hotel or coffee shop? A Virtual Private Network (VPN) allows...
Friday, July 3, 2015
How To Set Up Automatic Deployment with Git with a VPS
Introduction
For an introduction to Git and how to install, please refer to the introduction tutorial.
This article will teach you how to use Git when you want to deploy your application. While there are many ways to use Git to deploy our application, this tutorial will focus on the one that is most straightforward....
How To Set Up Apache Virtual Hosts on Ubuntu 14.04 LTS
Introduction
The Apache web server is the most popular way of serving web content on the internet. It accounts for more than half of all active websites on the internet and is extremely powerful and flexible....
How To Install Linux, Apache, MySQL, PHP (LAMP) stack on Ubuntu 14.04
Introduction
A "LAMP" stack is a group of open source software that is typically installed together to enable a server to host dynamic websites and web apps. This term is actually an acronym which represents the Linux...
Understanding the Nginx Configuration File Structure and Configuration Contexts
Introduction
Nginx is a high performance web server that is responsible for handling the load of some of the largest sites on the internet. It is especially good at handling many concurrent connections and excels at serving...
Additional Recommended Steps for New Ubuntu 14.04 Servers
Introduction
After setting up the bare minimum configuration for a new server, there are some additional steps that are highly recommended in most cases. In this guide, we'll continue the configuration of our servers by tackling some recommended, but optional procedures....
Thursday, July 2, 2015
Initial Server Setup with Ubuntu 14.04
Introduction
When you first create a new Ubuntu 14.04 server, there are a few configuration steps that you should take early on as part of the basic setup. This will increase the security and usability of your server and will give you a solid foundation for subsequent actions....
Understanding Nginx HTTP Proxying, Load Balancing, Buffering, and Caching
Introduction
In this guide, we will discuss Nginx's http proxying capabilities, which allow Nginx to pass requests off to backend http servers for further processing. Nginx is often set up as a reverse proxy solution to...
How To Install Linux, nginx, MySQL, PHP (LEMP) stack on Ubuntu 14.04
Introduction
The LEMP software stack is a group of software that can be used to serve dynamic web pages and web applications. This is an acronym that describes a Linux operating system, with an Nginx web server. The backend data is stored in MySQL and the dynamic processing is handled by PHP.
In this guide, we will demonstrate...
How To Set Up Nginx Server Blocks (Virtual Hosts) on Ubuntu 14.04 LTS
Introduction
When using the Nginx web server, server blocks (similar to the virtual hosts in Apache) can be used to encapsulate configuration details and host more than one domain off of a single server.
In this guide, we'll discuss how to configure server blocks in Nginx on an Ubuntu 14.04 server....
How To Set Up SSH Keys
About SSH Keys
SSH keys provide a more secure way of logging into a virtual private server with SSH than using a password alone. While a password can eventually be cracked with a brute force attack, SSH keys are nearly...
How To Add Swap on Ubuntu 14.04
Introduction
One of the easiest way of increasing the responsiveness of your server and guarding against out of memory errors in your applications is to add some swap space. Swap is an area on a hard drive that has been designated as a place where the operating system can temporarily store data that it can no longer...
Wednesday, July 1, 2015
How To Set Up a Firewall Using IPTables on Ubuntu 14.04
Introduction
Setting up a good firewall is an essential step to take in securing any modern operating system. Most Linux distributions ship with a few different firewall tools that we can use to configure our firewalls. In this guide, we'll be covering the iptables firewall....
How To Use NSD, an Authoritative-Only DNS Server, on Ubuntu 14.04
Introduction
Setting up a DNS server to be responsible for domain names can be a complex task even for seasoned administrators. DNS zone management is a vital duty, but can be bewildering, especially when attempting to get started.
Software like the Bind DNS server is incredibly flexible and can be configured to...
How To Configure BIND as a Private Network DNS Server on Ubuntu 14.04
Introduction
An important part of managing server configuration and infrastructure includes maintaining an easy way to look up network interfaces and IP addresses by name, by setting up a proper Domain Name System (DNS)....
How To Configure Bind as an Authoritative-Only DNS Server on Ubuntu 14.04
Introduction
DNS, or the Domain Name System, is often a difficult component to get right when learning how to configure websites and servers. While most people will probably choose to use the DNS servers provided by their hosting company or their domain registrar, there are some advantages to creating your own DNS server...
How To Configure Bind as a Caching or Forwarding DNS Server on Ubuntu 14.04
Introduction
DNS, or the Domain Name System, is often a difficult component to get right when learning how to configure websites and servers. While most people will probably choose to use the DNS servers provided by their hosting company or their domain registrar, there are some advantages to creating your own DNS server...
How To Set Up a Host Name with DigitalOcean
DigitalOcean’s DNS allows you to easily set up your hostname from the DigitalOcean control panel.
Setup
Before you get started, you do need to have the following:
A Droplet (virtual private server) from DigitalOcean. If you don’t have one, you can register and set one up in under a minute
A Registered Domain...
A Comparison of DNS Server Types: How To Choose the Right DNS Configuration
Introduction
DNS, or the Domain Name System, is an integral part of how systems connect with each other to communicate on the internet. Without DNS, computers, and the people who use them, would be required to connect using only numerical addresses known as IP addresses....
An Introduction to DNS Terminology, Components, and Concepts
Introduction
DNS, or the Domain Name System, is often a very difficult part of learning how to configure websites and servers. Understanding how DNS works will help you diagnose problems with configuring access to your websites and will allow you to broaden your understanding of what's going on behind the scenes....
How To Create a New User and Grant Permissions in MySQL
About MySQL
MySQL is an open source database management software that helps users store, organize, and later retrieve data. It has a variety of options to grant specific users nuanced permissions within the tables and databases—this tutorial will give a short overview of a few of the many options....
How To Install Wordpress on Ubuntu 14.04
Introduction
At this time, WordPress is the most popular CMS (content management system) on the internet. It allows you to easily set up flexible blogs and websites on top of a MySQL backend with PHP processing. WordPress has seen incredible adoption and is a great choice for getting a website up and running quickly.
In...
How To Install Java on Ubuntu with Apt-Get
Introduction
As a lot of articles and programs require to have Java installed, this article will guide you through the process of installing and managing different versions of Java....
How To Install and Secure phpMyAdmin on Ubuntu 14.04
Introduction
While many users need the functionality of a database management system like MySQL, they may not feel comfortable interacting with the system solely from the MySQL prompt.
phpMyAdmin was created so that...
5 Ways to Improve your Production Web Application Server Setup
Introduction
Once your application is up and running in a cloud server environment, you may be wondering how you can improve your server environment to make the leap from "it works" to a full-fledged production environment....
An Introduction to Securing your Linux VPS
Introduction
Taking control of your own Linux server is an opportunity to try new things and leverage the power and flexibility of a great platform. However, Linux server administrators must take the same caution that is appropriate with any network-connected machine to keep it secure and safe.
There are many different security...
A Basic MySQL Tutorial
About MySQL
MySQL is an open source database management software that helps users store, organize, and retrieve data. It is a very powerful program with a lot of flexibility—this tutorial will provide the simplest introduction to MySQL
How to Install MySQL on Ubuntu and CentOS
If you don't have MySQL installed on your...
How To Configure a Mail Server Using Postfix, Dovecot, MySQL, and SpamAssassin
Introduction
In this tutorial, we are going to configure a mail server using Postfix, Dovecot, MySQL and SpamAssassin on Ubuntu 12.04.
Following this tutorial you'll be able to add virtual domains, users, and aliases. Moreover, your virtual server will be secure from spam hub....
How To Setup Your Own VPN With PPTP
Intro
One of the commonly asked questions from our users is how to add another IP address to their server. You can assign your own private IP address to your droplet by creating a VPN tunnel. Whether you want to build your own Virtual Private Network (VPN), or assign an SSL certificate to that IP address, you have several...
DNS Server - 3 Start Bind
Start BIND.
[root@dlp ~]# systemctl start named
[root@dlp ~]# systemctl enable named
Change DNS settings that the server refer to local DNS servic...
DNS Server - 2 Set Zone
Create zone files that servers resolve IP address from domain name
For internal zone
This example uses internal address[10.0.0.0/24], domain name[server.world], but please use your own one when you set config on your server....
DNS Server - 1 Install BIND
Install BIND to configure DNS server which resolves domain name or IP address. BIND uses 53/TCP,UDP
Install BIND.
[root@dlp ~]# yum -y install bind bind-utils...
SSH Server CentOS 7
Configure SSH Server - Password Authentification
Configure SSH Server to manage a server from the remore computer. SSH uses 22/TCP
SSHd is installed even if you installed CentOS with "Minimal Install", so it's not necessarry to install new packages. Furthermore, SSHd is set auto-start setting by default, so it's possible...
Tuesday, June 30, 2015
NTP Server CentOS 7
NTPD - Configure NTP Server
Install NTPd and Configure NTP server for time adjustment. NTP uses 123/UDP
[root@dlp ~]#
yum -y install ntp
[root@dlp ~]#
vi /etc/ntp.conf
...
Initial Setting CentOS 7 - Configure VIM
Install and Configure vim that is more convenience than vi.
Install vim
[root@dlp ~]# yum -y install vim-enhanced
Set command alias. ( Apply to all users below. If you apply to a user, Write the same settings in '~/.bashrc' )
[root@dlp ~]#
vi /etc/profile
# add at the last line
alias vi='vim'
[root@dlp...
Initial Setting CentOS 7 - Add Repository
Add some useful external repositories to install useful softwares
Install a plugin to add priorities to each installed repositories.
[root@dlp ~]#
yum -y install yum-plugin-priorities
# set [priority=1] to official repository
[root@dlp ~]# sed -i -e "s/\]$/\]\npriority=1/g" /etc/yum.repos.d/CentOS-Base.rep...
Initial Setting CentOS 7 - Update System
After installing CentOS, Update the system first if possible.
[root@dlp ~]# yum -y update ...
Initial Setting CentOS 7 - Services
It's possible to make sure services' status like follows
# display the list of services which are running
[root@dlp ~]#
systemctl -t service ...
Initial Seting CentOS 7 - Network Setting
Set static IP address to the server
Replace the interface name "eno16777736" for your own environment's one
# set hostname
[root@localhost ~]#
hostnamectl set-hostname dlp.server.world
# display devic...
Initial Setting CentOS 7 - Firewall and Selinux
FIREWALL
If the Firewall on the server is unnecessarry (for example, because some firewalls are allready running in your LAN ),
then stop it like follows.
If needs, refer to here to configure Firewalld.
[root@dlp ~]#
systemctl stop firewalld
[root@dlp ~]#
systemctl disable firewalld
rm...
Basic Operation of Firewalld Centos 7
This is the Basic Operation of Firewalld.
The definition of services is set to zones on Firewalld. To enable Firewall, assosiate a zone to a NIC with related commands.
1. To use Firewalld, start it
[root@dlp ~]#
systemctl start firewalld
[root@dlp ~]#
systemctl enable firewalld ...
Initial Setting CentOS 7 - Add an User
Add an User "cent" as an example below.
[root@dlp ~]#
useradd cent
[root@dlp ~]#
passwd cent
Changing password for user cent.New UNIX password:
# set password
Retype new UNIX password:
# confirm
passwd: all authentication tokens updated successfully.[root@dlp ~]#
exit&nb...
Install Centos 7
Insert CentOS install disk and start the Computer. Then, Following screen is displayed, Push Enter key to proceed.
...
Thursday, June 18, 2015
Debian/Ubuntu Linux: Restrict an SSH user session to a specific directory by setting chrooted jail
I setup a web-server. I need to grant a user ssh access but I do not trust users. How can I limit user session to a specific directory such as /home/httpd/$USERNAME? How do I set up a ssh chroort jail on a Linux operating systems?You can interactive shell with special root directory on a Linux or Unix-like systems. You can...
Thursday, May 21, 2015
SSH ProxyCommand example: Going through one host to reach another server
How do I use and jump through one server to reach another using ssh on a Linux or Unix-like systems? Is it possible to connect to another host via an intermediary so that the client can act as if the connection were direct using ssh?
You can jump host using ProxyCommand.Some times you can only access a remote server via ssh...
Linux exit from lxc-console keyboard shortcut
I'm using Debian Linux server with Linux Containers (lxc). How do I disconnect and exit from an lxc-console to a shell prompt without closing ssh session?You need to use the lxc-console command to log in to a running Linux container. The syntax is as follows...
Wednesday, May 20, 2015
How to run sudo command without a password on a Linux or Unix
'm a new Unix system user. How do I use sudo command without a password on a Linux or Unix-like systems?Some times you may need to run a command with root privileges, but you do not want to type a password using sudo command. This is useful for scripting or any other purpose. This can be achieved by editing /etc/sudoers file...
Sunday, May 17, 2015
How To Patch and Protect Linux Server Against the VENOM Vulnerability # CVE-2015-3456
A very serious security problem has been found in the virtual floppy drive QEMU's code used by many computer virtualization platforms including Xen, KVM, VirtualBox, and the native QEMU client. It is called VENOM vulnerability. How can I fix VENOM vulnerability and protect my Linux server against the attack? How do I verify...
Saturday, May 16, 2015
How To CentOS / RHEL 7 Install Gnome Desktop Using Yum
I installed minimal CentOS Linux 7.x on my laptop. How can I install Gnome desktop GUI on a RHEL (Red Hat) 7 or CentOS Linux 7 system using command line option?GNOME is a highly intuitive and user friendly desktop environment for CentOS and RHEL 7.x based system. If you did a minimal install, this guide will quicly...
Friday, May 15, 2015
Linux/Unix: OpenSSH Multiplexer To Speed Up OpenSSH Connections
ow can I multiplex SSH sessions by setting up a master session and then having subsequent sessions go through the master to speed up my ssh connection on a Linux or Unix-like operating systems?Multiplexing is nothing but send more than one ssh connection over a single connection. OpenSSH can reuse an existing TCP connection...
Tuesday, May 12, 2015
RHEL / Centos Linux 7: Change and Set Hostname Command
I'm a new RHEL (Red Hat Linux) and/or CentOS Linux 7 server user. How can I change the hostname in CentOS 7 using a command line option?On a CentOS Linux 7 server you can use any one of the following tool to manage hostnames...
Monday, May 11, 2015
CentOS/RHEL Use yum Command To Downgrade or Rollback Updates
I'm a CentOS Linux 7.x server user. How can I use yum command to downgrade or rollback package updates on a RHEL (Red Hat)/CentOS/Scientific Linux server?In this tutorial, you will learn:
How to downgrade installed packages using YUM
How to rollback installed package to previous version
The following examples only...
Sunday, May 10, 2015
HowTo Block Internet Explorer Browser With Squid Proxy Server on a Linux/Unix Server
I want to block Internet Explorer (MS-IE) browser on a squid proxy server running on a Linux or Unix-like systems. How can I block IE on a squid proxy server version 3.x?
You need to setup an acl on a squid proxy server to block Microsoft Internet Explorer or any other browser of your choice. This tutorials explains how...
Wednesday, May 6, 2015
RHEL / CentOS Linux 7 Enable Ping Access In Docker Container
I'm using RHEL 7.1-4 container on a RHEL /CentOS Linux 7.x server. However, I'm unable to ping external site/IP address using the ping command. I'm getting the following error on screen:
ping: Operation not permitted
How do I fix this problem?Linux kernel v2.2+, divides the privileges traditionally associated with superuser...
Tuesday, May 5, 2015
HowTo Debian/Ubuntu Linux Auto Mount Windows NTFS File System [ntfs-3g]
I'm dual booting MS-Windows with a Debian / Ubuntu Linux desktop. How can I auto mount a drive containing a MS-Windows NTFS file system on a Linux based systems?The New Technology File System (NTFS) is a file system developed by Microsoft in 1995 with Windows NT. You can easily auto mount a hard disk drive partition containing...
Monday, May 4, 2015
Debian/Ubuntu Linux: Find If Installed Package Includes a Fix/Patch Via CVE Number
I am a Debian Linux serer user. How do I view the changelog of an installed package and find out if given CVE includes a fix or patch? How do I see a fix or patch already applied to installed package on a Ubuntu or Debian LTS server?The changelog of an installed package is usaully stored as follows on a Debian or Ubuntu...
Saturday, March 21, 2015
How To Patch and Protect OpenSSL Vulnerability # CVE-2015-0291 CVE-2015-0204 [ 19/March/2015 ]
On 19th March 2015, multiple high and moderate severity level vulnerabilities released in OpenSSL, a Secure Sockets Layer toolkit used in a Linux and Unix-like systems. How can I fix these vulnerabilities on a CentOS/RHEL/Ubuntu and Debian Linux based server for OpenSSL versions 1.0.2a, 1.0.1m, 1.0.0r, and 0.9.8zf.? How do...
