May 19, 2012

Creating Multi Domain Java Key Store

You often may need to access to a host with different host headers. By means of the subjectAltName field introduced in X.509 v3, we are able to specify multiple domains in a single certificate. You can create certificate requests including subjectAltName field by openssl tool. On the other hand, lots of applications require certificates in Java Key Stores. In our case, we should have achieved to configure VMware View Connection Servers with multiple host headers. Since i am familiar with openssl, i have done it in the following way.

August 12, 2011

20th Anniversary of Linux (LinuxCon)

Memorable Linux Milestones

1991 - Linus Torvalds posts Famous Message - "Hello everybody out there..." - and releases first linux code
1992 - Linus licenses Linux under the GPL, an important decision that will contribute to its success in the coming years
1993 - Slackware becomes first widely adopted distribution
1996 - Linus visits aquarium, gets bit by a penguin and chooses it as linux mascot
1998 - Tech giants begin announcing platform support for Linux
1999 - Red Hat goes public
2003 - IBM runs famous Linux ad during the Superbowl
2005 - Linus appears on the cover of Businessweek with a story that hails Linux as a business success
2007 - The Linux Foundation is formed to promote, protect and standardize Linux, Linus is a fellow
2010 - The Linux-based Android OS outships, all other smartphone OSes in the U.S. and climbs to dominance
2011 - Linux turns 20 and powers the world's supercomputers, stock exchanges, phones, ATMs, healthcare, records, smard grids, the list goes on


May 5, 2011

ITIL v3 Service Lifecycle Model from

Service Strategy
Service Transition
Continual Service Improvement
Strategy Generation
Transition Planning and Support
7-Step Improvement Process
Financial Management
Change Management
Service Measurement
Service Portfolio Management
Service Asset & Configuration Mgmt
Service Reporting
Demand Management
Release and Deployment Mgmt

Service Validation and Testing

Service Design

Service Catalogue Management
Knowledge Management

Service Level Management

Capacity Management
Service Operation

Availability Management
Event Management

IT Service Continuity Management
Incident Management

Information Security Management
Request Fulfilment

Supplier Management
Problem Management

Access Management

Poster! ITIL v3 Service Lifecycle model ( Download

March 17, 2011

Customizing Daylight Saving Time

Get the tzdata source rpm package. It can be directly downloaded from$releasever/os/SRPMS/
It is better to create a source yum repository.
Create a file /etc/yum.repos.d/source.repo
name=CentOS $releaserver - $basearch - Source
Install yum-utils for yumdownloader

December 15, 2010

Cloud Computing

Cloud Computing? Parallel Computing? Distributed Computing? Grid Computing? Cluster Computing? Utility Computing? Virtualization? SOA? HPC?

“The interesting thing about cloud computing is that we’ve redefined cloud computing to include everything that we already do.” (Larry Ellision, Oracle’s CEO)

"Computing may someday be organized as a public utility just as the telephone system is a public utility..." (John McCarthy speaking at the MIT Centennial in 1961)

"Cloud computing is simply a trap aimed at forcing more people to buy into locked, proprietary systems that would cost them more and more over time" (Richard Stallman, Free Software Foundation founder)

A lot of people are jumping on the bandwagon of cloud, but I have not heard two people say the same thing about it," said Andy Isherwood, HP's vice president for software services in Europe. 
In fact, NIST has a consistent definition of cloud computing.

April 2, 2010

MySQL Replication on RHEL | CentOS 5

Configuration of master server /etc/mysql/my.cnf
log-bin = / var/log/mysql/master-bin.log
log-bin-index = /var/lib/mysql/master-log-bin.index

September 16, 2009

GFS Cluster on VMware vSphere (RHEL | CentOS 5)

First of all, to make vms access to shared block devices, a new scsi controller must be created. The controller must be configured as physical scsi bus sharing to make vms distribute among hosts. Raw devices are recommended. Keep in mind, ha, drs and snapshot features are disabled for the vms that have shared disks.

Install the clustering packages on vms
# yum groupinstall Clustering Cluster\ Storage -y
Install vmware-ng for fencing