Author: Rahul

I, Rahul Kumar am the founder and chief editor of TecAdmin.net. I am a Red Hat Certified Engineer (RHCE) and working as an IT professional since 2009..

Openfire is a real time collaboration server. It uses XMPP protocol for instant messaging. This tutorial will help you to install and configure your won instant messaging server using Openfire and Spark. You can configure it to use in your LAN as well as over internet also. Step 1 – Prerequisites Before installing Openfire make sure you have java installed on your system. If you do not have Java installed use following tutorials to install Java on your system. How to Install Oracle JAVA 8 on Debian How to Install Oracle JAVA 8 on Ubuntu & LinuxMint How to Install…

Read More

Varnish is an Web accelerator used for content-heavy dynamic web sites. Its used as front-end caching server for web servers. This tutorial will help you to setup Varnish on your System. Step 1: Add Atomic Repository There are latest release available in Atomic repository in RPM format. For RHEL/CentOS 5: # rpm -Uvh http://www6.atomicorp.com/channels/atomic/centos/5EL/i386/RPMS/atomic-release-1.0-16.el5.art.noarch.rpm For RHEL/CentOS 6: # rpm -Uvh http://www6.atomicorp.com/channels/atomic/centos/6/i386/RPMS/atomic-release-1.0-16.el6.art.noarch.rpm Step 2: Install Apache and Configure Use following commands to install Apache on your system. # yum install httpd Configure Apache to work on port 82. Edit Apache configuration file /etc/httpd/conf/httpd.conf and change value of Listen from 80 to…

Read More

Google Two-Factor Authentication provides next level of security from hackers to SSH server. This article will help you to how to protect your SSH server with an two-factor authentication using Google Authenticator PAM module. Now Every time when you try to ssh to your server, you have to generate code using your phone or other devices go get login. Step 1: Setup Required Repository First we need to add RPMForge yum repository in your system. Add this repository using one of the following commands. CentOS/RHEL 6, 32 Bit (i686): # rpm -Uvh http://packages.sw.be/rpmforge-release/rpmforge-release-0.5.2-2.el6.rf.i686.rpm CentOS/RHEL 6, 64 Bit (x86_64): # rpm…

Read More

Issue: Today, I found that /tmp was showing 100% full but, After deleting all files from /tmp it was still showing full. After google it, I found that there are some file which deleted from /tmp folder but still used by process used all space. Generally these files used by apache or mysql. Use following command to check files # lsof | grep /tmp mysqld 3236 mysql 6u REG 202,5 0 2373 /tmp/ibZzBzJ8 (deleted) mysqld 3236 mysql 7u REG 202,5 0 2378 /tmp/ibfoQY3a (deleted) mysqld 3236 mysql 11u REG 202,5 0 2393 /tmp/ibz2IDcI (deleted) mysqld 3236 mysql 220u REG 202,5…

Read More

Error: Below issue generally comes with database incompatibilities with the current version of MySQL. It may happen due to MySQL server upgrade or downgrade. Error in query (1548): Cannot load from mysql.proc. The table is probably corrupted Solution: This issue may resolve by repairing mysql databse using following command. # mysqlcheck -r mysql proc -u root -p Enter password: mysql.proc OK In case you are still getting same error while accessing proc table, You need to execute mysql_upgrade command to fix issue. Read more about mysql_upgrade # mysql_upgrade -u root -p

Read More

While installing magento, if you face issue like below, This the is known issue Error: Exception printing is disabled by default for security reasons. Error log record number: xxxxxx Solution: Step 1. Go to /errors/ folder in magento document root. Step 2. Copy local.xml.sample as local.xml # cp local.xml.sample local.xml Step 3. Edit magento/lib/Zend/Cache/Backend/File.php file, Find and change cache_dir setting. From: protected $_options = array( ‘cache_dir’ => ‘null’, To: protected $_options = array( ‘cache_dir’ => ‘tmp/’, Step 4. Finally create tmp folder in magento document root # mkdir tmp/ Step 5. done

Read More

Error: I faced following error after installing ffmpeg on our CentOS 6.5 server. ffmpeg: error while loading shared libraries: libavdevice.so.55: cannot open shared object file: No such file or directory Solution: In my case this issue comes, when we don’t not added codecs libraries path in ldconfig. I have fixed it by adding following entries in /etc/ld.so.conf. # vim /etc/ld.so.conf include ld.so.conf.d/*.conf /usr/lib /usr/local/lib Save file and run command # ldconfig All working now.

Read More

Wkhtmltopdf is a very useful application to create pdf from html (webpage). This article will help to create pdf of a webpage using php script and Linux command line tool. Step 1: Install wkhtmltopdf in Linux Download wkhtmltopdf from google code and install to linux system. # cd /opt # wget https://wkhtmltopdf.googlecode.com/files/wkhtmltopdf-0.9.9-static-i386.tar.bz2 # tar xjf wkhtmltopdf-0.9.9-static-i386.tar.bz2 # mv wkhtmltopdf-i386 /usr/bin/wkhtmltopdf # chown apache:apache /usr/bin/wkhtmltopdf # chmod +x /usr/bin/wkhtmltopdf Step 2: Create Pdf Using Command Line First check wkhtmltopdf script it its properly working from command line. Below command will create pdf of http://google.com web page. # /usr/bin/wkhtmltopdf http://google.com google.pdf Step…

Read More

Public IP is used for communication between computers over the Internet. A computer running with public IP is accessible all over the world using the Internet. So we can say that it is the identity of the computer on the internet. Now the question is how do we know our public IP?. For computers having GUI can easily get there IP using web tools like this but how to get public IP of the computers having terminal access only. The solution is here – use one of the following commands to find public IP of your system using Linux terminal.…

Read More

VLC is a free, open-source, and cross-platform multimedia player. It’s useful to play music and videos on the system. This article will help you to install VLC on Fedora Systems. This tutorial provides you two methods for installing VLC on Fedora systems. The first method will use the Snap package to install VLC and the second method will use the traditional way with rpm repositories for installing VLC on the Fedora system. Method 1 – Installing VLC on Fedora via Snap The Snapcraft is the latest way for installing Packages on Linux systems. It provides cross-platform applications to install on…

Read More