HowTo: Use OpenBSD In the Corporate Environment

Posted on in Categories OpenBSD last updated April 20, 2011

OpenBSD has a reputation for high security and difficult operating systems for new user. But, some orginsations are using OpenBSD for everything including firewall, servers and desktop computers. This is quite impressive, from the article:

So our paid job is hacking on and deploying, maintaining, supporting… OpenBSD installations. We are also required to hack on things that can be merged back into OpenBSD itself and when it’s not possible, then we change what we did so that it can be. Of course some developments are very specific to what we do and have no place in the project’s CVS tree.

So, amongst other services, we set up and maintain several 100% OpenBSD-based infrastructures (going from the entry site firewall to the secretary’s workstation) and this is what I’m going to talk about here.

As a side note, it is important to know that we are working exclusively for Fortune 500 companies (each operating in totally different and unrelated sectors).

Read more: A Puffy in the corporate aquarium.

Getting Yesterdays or Tomorrows Day With Bash Shell Date Command

Posted on in Categories Howto, Linux, Shell scripting, Tips, UNIX last updated June 15, 2011

When invoked without arguments, the date command displays the current date and time. Depending on the options specified, date will set the date and time or print it in a user defined way. I’ve seen many sysadmin writing perl scripts for calculating relative date such as yesterdays or tomorrows day. You can use GNU date command, which is designed to handle relative date calculation such as:

  • 1 Year
  • 2 Days
  • 2 Days ago
  • 5 Years

List of open source cluster management systems

Posted on in Categories Beyond nixCraft last updated March 27, 2008

M. Shuaib Khan has published a list of open-source cluster management systems.

Personally, I had used openMosix and Red Hat Cluster software (which is also based upon open source software funded by Red Hat).

From the article: In computing world, the term “cluster” refers to a group of independent computers combined through software and networking, which is often used to run highly compute-intensive jobs. With a cluster, you can build a high-speed supercomputer out of hundreds or even thousands of relatively low-speed systems. Cluster management software offers an easy-to-use interface for managing clusters, and automates the process of queuing jobs, matching the requirements of a job and the resources available to the cluster, and migrating jobs across the cluster:

=> openMosix
=> Kerrighed
=> OpenSSI
=> Gluster
=> BOINC

Read this article it offers feature, cons and pros of each solution.

Howto: Shutdown Linux Box Automatically

Posted on in Categories CentOS, Debian Linux, Gentoo Linux, Howto, Linux, Suse Linux, Sys admin, Tips, UNIX last updated January 9, 2010

You may wonder – why should I shutdown the Linux box box automatically? It depends upon your situation. For example, your downloading couple of tar balls and you want to go home. You can schedule a job to shutdown Linux after downloading is completed. Linux/UNIX/BSD/OS X comes with at and cron commands to automate task. Almost all common task can be automated using at command.