Step 1 The setup
Here is your Ubuntu serve box with two interfaces,
eth0————-Internet
eth2————-Internal
Note: Your Internet is running using eth0.
Step1: Install DHCP Server
#apt-get install dhcp3-server
Creating an Ubuntu Router
Configurations (Linux)
Install Openfiler from USB
The problem we have now is our storage server has no optical drive and we do not have any external optical drive available here in office. Alternatively, we can use USB stick drive and make sure our server are able to boot from USB.
Server: DELL PowerEdge R510
OS version: Openfiler 2.99 64bit
USB flash drive: /dev/sdb
RAID 10 virtual disk: /dev/sda
Preparing the Flash Drive
1. Download the ISO from here into your local PC. In my case, I downloaded the x86_64 distribution ISO.
Install and Configure Zenoss as Centralized Monitoring System
Good system administrator should know that they need to do these 3 most important things after delivering a server:
secure
monitor
backup
As part of monitoring task, in this tutorial, I am going to show on how to build a centralized monitoring system using Zenoss. Zenoss will need to use SNMP agent in every server that need to be monitored. If you have high number of servers, you should use Zenoss instead of Cacti or Nagios because it is easier to setup and maintain. The web-based management portal is really easy to understand and you can monitor a lot of things, not limited to SNMP MIB reporting only.
Zenoss has the community version which is free. The latest version of Zenoss at this date is version 4. Zenoss installer recommending user to use a clean server. But in my case, I will use a cPanel server which really not heavy in usage for this purpose. In order to run Zenoss in ‘not-so-clean’ server, I need to use Zenoss stack version 3. I will be using following variables:
OS: RHEL 5.3 64bit (Tikanga)
cPanel: 11.32.3 (build 23)
Zenoss server IP: 210.20.88.50
Server to be monitored: 177.60.52.200 and 81.71.46.44
LSyncd
I have a situation where there is one critical website under our company server is critically need to be sync to our backup server. Sync means whatever changes happen in master server, it will replicated to slave server. Yes, you can rsync. But, I do not want to schedule the task as cron to sync. There is one tool which is better than that and very suitable to be applied in this situation called lsyncd.
Lsyncd watches a local directory trees event monitor interface (inotify or fsevents). It aggregates and combines events for a few seconds and then spawns one (or more) process(es) to synchronize the changes. By default this is rsync. Lsyncd is thus a light-weight live mirror solution that is comparatively easy to install not requiring new filesystems or blockdevices and does not hamper local filesystem performance.
High Availability: Configure Piranha for HTTP, HTTPS and MySQL
In this post we will complete over the Piranha configuration with HTTP and HTTPS load balancing using direct-routing with firewall marks and MySQL load balancing using direct-routing only.
HTTP/HTTPS will need to be accessed by users via virtual public IP 130.44.50.120 while MySQL service will be accessed by web servers using virtual private IP 192.168.100.30. Kindly refer to picture below for the full architecture:
All Servers
SELINUX must be turned off on all servers. Change the SELINUX configuration file at /etc/sysconfig/selinux:
Manage Multiple MySQL Servers using PHPmyAdmin
In my environment, I have 5 different MySQL database servers running separately under different geographical location. Since it run standalone and not in cluster mode, I need to have one platform to manage these database servers altogether.
PHPmyAdmin is able to do this, with some changes on the configuration files. You just need to allow the MySQL user and host on every database server to be connected to. The setup that I am going to do will be as below:
CentOS: Configure Piranha as Load Balancer (Direct Routing Method)
I am currently working on a web cluster project using CentOS. In this project, I have 2 web servers running on Apache and mounted the same document root to serve the HTTP content. I also have 2 servers in front of it to become the load balancer and failover to increase high availability of the two-node web server cluster. The virtual IP will be hold by load balancer #1 with auto failover to load balancer #2.
You may refer to diagram below to get clearer picture:
I am using following variables:
All servers’ OS: CentOS 6.2 64bit
Web server #1: 192.168.0.221
Web server #2: 192.168.0.222
Load balancer #1: 192.168.0.231
Load balancer #2: 192.168.0.232
Virtual IP: 192.168.0.220
Load Balancer Server
1. All steps should be done in both servers unless specified. We will install Piranha and other required packages using yum:
Munin adding up new eth interface
root@pluto:/usr/share/munin/plugins# ./if_ suggest
ath0
eth0
–shell
munin-node-configure –shell creates symlink commands to link useful plugins from the plugin library to the plugin service directory (usually /etc/munin/plugins).
To continue the if_ example:
root@pluto:/usr/share/munin/plugins# munin-node-configure –shell
ln -s /usr/share/munin/plugins/if_ /etc/munin/plugins/if_ath0
ln -s /usr/share/munin/plugins/if_ /etc/munin/plugins/if_eth0
Centos Install and Configure MRTG
The Multi Router Traffic Grapher (MRTG) is a tool to monitor the traffic load on network-links.
MRTG generates HTML pages containing PNG images which provide a LIVE visual representation of this traffic. You need the following packages:
mrtg : Multi Router Traffic Grapher
net-snmp and net-snmp-utils : SNMP (Simple Network Management Protocol) is a protocol used for network management. The NET-SNMP project includes various SNMP tools. net-snmp package contains the snmpd and snmptrapd daemons, documentation, etc. You also want to install the net-snmp-utils package, which contains NET-SNMP utilities.
This FAQ works with RHEL / CentOS and Fedora Linux.
Using DKIM to Authenticate Email Message
Domain Keys Identified Mail (DKIM) defines a domain-level authentication mechanism that lets your organization take responsibility for transmitting an email message in a way that can be verified by a recipient. Your organization can be the originating sending site or an intermediary. Your organization’s reputation is the basis for evaluating whether to trust the message delivery.
You can add a DKIM digital signature to outgoing email messages, associating the message with a domain name of your organization. You can enable DKIM signing for any number of domains that are being hosted by ZCS. It is not required for all domains to have DKIM signing enabled for the feature to work.
DKIM defines an authentication mechanism for email using