The first step is to download, build and install HAProxy. We highly recommend version 1.3.15.4 or later. wget http://haproxy.1wt.eu/download/1.4/src/haproxy-1.4.15.tar.gz tar xvzf haproxy* cd haproxy* make TARGET=linux26 cp haproxy /usr/ sudo install –owner=root –group=root -m700 haproxy /usr/sbin/ Configuring the proxy server Copy the following configuration file. global # maximum number of simultaneous active connections from an Read More…
Zimbra using Gmail Mail Relay
May 10th, 2011 by Pawan Kumar View Comments »Setting up gmail as a mail relay You won’t be able to send or receive mail yet as you don’t have a mail relay set up. You can specify your ISPs mail server here or do what I do and use googles gmail servers.su – zimbra zmprov ms mail.soundlinuxtraining.com zimbraMtaRelayHost smtp.gmail.com:587 echo smtp.gmail.com username:password > Read More…
Linux Server Hardening Security Tips
May 9th, 2011 by Chandra View Comments »Securing your Linux server is important to protect your data, intellectual property, and time, from the hands of crackers (hackers). The system administrator is responsible for security Linux box. In this first part of a Linux server security series, I will provide 20 hardening tips for default installation of Linux system. #1: Encrypt Data Communication Read More…
Allow multiple RDP sessions to a Windows 2008 server
May 9th, 2011 by Chandra View Comments »By default Windows 2008 only allows a user one single session over RDP. While in some instances this can be quite handy, if like me, you have multiple developers working on a single server, your frustration from being randomly logged out by a colleague can come to the boil. Quick and easy solution. Log in Read More…
How round a number in bash script
April 26th, 2011 by Manoj Chauhan View Comments »In a shell script – How do I round a decimal number (contained in a variable) to the nearest whole number? var=2.5 echo $var|awk ‘{print int($1+0.5)}’ Output is 2 round a number In a shell script – How do I round a decimal number (contained in a variable) to the nearest whole number?
Zimbra Intergration with Open LDAP
April 22nd, 2011 by Pawan Kumar View Comments »I have Zimbra Collaboration Suite installed Now I wanted to integrate it to Open Directory for authentication purposes. The problem is though that Zimbra does not make this easy, especially when dealing with SSL certificates. Here’s what I did step by step Install Zimbra 1. Download and install the Zimbra package, 1.1 Next, verify your Read More…
Clamav update on Zimbra Mail server
April 22nd, 2011 by Pawan Kumar View Comments »Clamav update is required if one day support for certain versions of clamav terminated. To be able to update Clamav in the Mail Server Zimbra actually not too difficult of origin according to the procedure, the following steps: Download Clamav version on it or the most recent The latest version now is Clamav 0.96, but Read More…
Self-signed certificate in Glassfish Web Server
April 14th, 2011 by Chandra View Comments »Use keytool to generate, import, and export certificates. By default, keytool creates a keystore file in the directory where it is run. You can find the keytool utility under the bin directory of java folder. Note: – When you install Glassfish, it creates a default self-signed certificate as the server certificate. (localhost) Delete exiting certificate Read More…
Virtualization using Xen on Ubuntu
April 14th, 2011 by Pawan Kumar View Comments »Xen is the open source virtualization solution .This blog is about installing a new Xen server on Ubuntu 10.04. Also I have the composite window manager on top of the Xen! With full 3D support! To achieve this I do: 1- Install your Ubuntu Desktop 10.4 and upgrade your system; 1.1 – Install some packages: Read More…
Administering the Kerberos Database
April 3rd, 2011 by Manoj Chauhan View Comments »Configuring a Kerberos 5 Server To configure a basic Kerberos server, follow these steps: 1. Be sure that you have clock synchronization and DNS working on your server before configuring Kerberos 5. Pay particular attention to time synchronization between the Kerberos server and its various clients. If the server and client clocks are different by Read More…
What is the Oracle voting disk used for?
March 27th, 2011 by Manoj Chauhan View Comments »A voting disk is a backup communications mechanism that allows CSS daemons to negotiate which subcluster will survive. These voting disks keep a status of who is currently alive and counts votes in case of a cluster reconfiguration. It works as follows: a) Ensures that you cannot join the cluster if you cannot access the Read More…
How do I configure raw devices in order to install 10g Clusterware on RHEL5 or OEL5?
March 27th, 2011 by Manoj Chauhan View Comments »The raw devices OS support scripts like /etc/sysconfig/rawdevices are not shipped on RHEL5 or OEL5, this is because raw devices are being deprecated on Linux. This means that in order to install 10g Clusterware you’d have to manually bind the raw devices to the block devices for the OCR and voting disks so that the Read More…
Is the hangcheck timer still needed with Oracle RAC 10g and 11g?
March 27th, 2011 by Manoj Chauhan View Comments »YES! The hangcheck-timer module monitors the Linux kernel for extended operating system hangs that could affect the reliability of the RAC node ( I/O fencing) and cause database corruption. To verify the hangcheck-timer module is running on every node: as root user: /sbin/lsmod | grep hangcheck If the hangcheck-timer module is not listed enter the Read More…
Disk i/o & Performance Tuning Benchmarking Tool
March 25th, 2011 by Manoj Chauhan View Comments »Disk i/o & Performance Tuning Benchmarking Tool Dstat is a flexible replacement for vmstat, iostat, netstat and ifstat. Dstat overcomes some of their limitations and adds some extra features. Dstat is handy for monitoring systems during performance tuning tests, disk i/o, benchmarks or troubleshooting. Dstat allows you to view all of your system resources in Read More…
Domain Catchall in postfix
March 23rd, 2011 by Pawan Kumar View Comments »Hi, If you want to set up an account “user@abc.org” to catch all any mail not delivered to existing users in the domain “abc.org”, you can configure the account as a domain catchall. If the users “admin@abc.org”, “webmaster@abc.org”, and “nobody@abc.org” don’t exist, and mail arrives for them, it will be delivered to the catchall account Read More…
