August 18, 2011
by Mohan Cheema
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Screen is a much under utilised program, which provides the following functionality:
November 1, 2010
by Mohan Cheema
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This is a step by step guide on how to configure GNU/Linux system with Postfix, OpenLDAP, Courier-imap, Amavisd-new, SpamAssassin and clamav. Even though this setup was configured on Centos 5, with minor tweaks you should get it working on any GNU/Linux distribution.
Building necessary software
October 11, 2010
by Mohan Cheema
1 Comment
So you forgot your root password of your linux box?, well its not the end of the world if you do have physical / KVM over IP access to your box, you can start it on single user mode and reset it. Don’t know how?… then read on.
October 11, 2010
by Mohan Cheema
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One of the “must do’s” on setting a secure apache webserver environment is to disable directory listing. As a default Apache will be compiled with this option enabled, but its always a good idea to get rid of this setting unless its really necessary.
October 7, 2010
by Mohan Cheema
3 Comments
Introduction:
To explain what server loads really are and how to control them, how to watch loads and signs of server trouble.
October 6, 2010
by Mohan Cheema
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Many times on RHEL, haproxy is not reliable it gives an errors while connecting to apache backend, at that time it logs the following errors into /var/log/messages
kernel: ip_conntrack: table full, dropping packet
this is related to ip_conntrack kernel module.
If found this error message into /var/log/messages need to apply following steps
September 28, 2010
by Mohan Cheema
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If you notice the above message in syslog, it looks like the conntrack database doesn’t have enough entries for your environment. Connection tracking by default handles up to a certain number of simultaneous connections. This number is dependent on you system’s maximum memory size.
Some symptoms can be:
September 16, 2010
by Mohan Cheema
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Nov 04, 2003 Novell announced that they are acquiring SUSE linux and January 2004 the transaction was completed at approximate value of $210 million.
September 8, 2010
by Mohan Cheema
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In previous post we have setup Tomcat to run its multiple instances now we want that tomcat should start automatically on server reboots. This can be achieved by adding tomcat service script.
Introduction
This document will teach us how to setup Tomcat to run as a service (startup when booted) on Linux.
September 8, 2010
by Mohan Cheema
2 Comments
Introduction
This document will teach us how to setup Tomcat to run Multiple instances of it.
Intended Audience: System admins.
Instruction to installing Tomcat so that we can run multiple instances.
1. Install the Tomcat files