eAccelerator is a free open-source PHP accelerator, optimizer, and dynamic content cache. It increases the performance of PHP scripts by caching them in their compiled state, so that the overhead of compiling is almost completely eliminated. It also optimizes scripts to speed up their execution. eAccelerator typically reduces server load and increases the speed of your PHP code by 1-10 times. I have tested this...

Istanbul is a desktop session recorder for the Free Desktop. It records your session into an Ogg Theora video file. To start the recording, you click on its icon in the notification area. To stop you click its icon again. It works on GNOME, KDE, XFCE and others. It named Istanbul because, Istanbul as a tribute to Liverpool's 5th European Cup triumph in Istanbul on May 25th 2005. To install Istanbul, # yum...

As you login as “root” right from booting the system, all the privileges are set to root, what makes your system more vulnerable to your own mistakes and those wishing to enter your system. As you login as normal user, the privileges are limited, thus it´s safer. To be able to do administrative tasks you can temporally login as root using “su” in a console/terminal, that way the root privileges ...

Every time I connect to Linux server, I receive the same message and I’m getting tired of seeing it, so I decided to change the message to something else. Here’s the message that I get every time: [root@server1 ~]# ssh linuxarticles.org root@linuxarticles.org's password: Last login: Mon Oct 11 18:58:43 2010 from loc...

bzip2 compresses  files  using  the Burrows-Wheeler block sorting text compression algorithm, and Huffman coding.   Compression  is  generally considerably   better   than   that   achieved   by  more  conventional LZ77/LZ78-based compressors, and approaches the performance of the  PPM family of statistical compressors. To list the contents of a tar.bz2 file, use tar command as follows: ...

The mysqldump client is a backup program originally written by Igor Romanenko. It can be used to dump a database or a collection of databases for backup or transfer to another SQL server (not necessarily a MySQL server). The dump typically contains SQL statements to create the table, populate it, or both. However, mysqldump can also be used to generate files in CSV, other delimited text, or XML...

The default configuration for firewall is to reject all incoming packets from outside. To allow it, we need to open particular port in Firewall. The default configuration file for iptables based firewall under RHEL / CentOS / Fedora Linux is /etc/sysconfig/iptables. Open /etc/sysconfig/iptables, # vim /etc/sysconfig/iptables Append rule as follows: -A RH-Firewall-1-INPUT -m state...

MAC stands for Media Access Control and in a sense the MAC address is a computer's true name on a LAN. An Ethernet MAC address is a six byte number, usually expressed as a twelve digit hexadecimal number. To change this setting, we’ll need to edit the /etc/network/interfaces file. You can choose to use a different editor if you’d like. $ sudo gedit /etc/network/interfaces You s...

Backing up MySQL database is a very important system administration task, and should generally be run automatically from cron. We will use the mysqldump utility included with mysql to dump the contents of the database to a text file that can be easily restore. # mysqldump -h localhost -u root -p root_password DataBase > DB_name_Bkp.sql This will generate a text file containing ...

Dropbox is a Web-based file hosting service operated by Dropbox, Inc. which uses cloud computing to enable users to store and share files and folders with others across the Internet using file synchronization. It was founded in 2007 by MIT graduates Drew Houston and Arash Ferdowsi as a Y Combinator startup says Wikipedia.   To install DropBox on your system, download appropriate rpm for your...

Nowadays, GMail servers are very much reliable and give you a couple of GiBs for free of cost! So, it is the best place to store your linux system's important data. In order to accomplish this, first create a directory named “backup” in the root directory of your system: # cd / && mkdir backup Now, you need to create a script, which will perform backup and mail it for you...

If you are using Linux Desktop Operating System and do not want to set up an email server, use GMail account to relay emails. On Desktop OS, we can use GUI Email Clients, which supports POP3/IMAP to send an email but how about /usr/bin/mail or from cmd prompt? To fulfil your requirement, you need to install a simple program called ssmtp. It accepts a mail stream on standard input...

By default, when we are creating new user to Linux OS, all files from /etc/skel are copied to the new user's home directory. There are few files included in /etc/skel/ by default. * /etc/skel/.bash_logout * /etc/skel/.bashrc * /etc/skel/.profile * /etc/skel/.cshrc If you want to share some files, including rules and regulations to new users, simply add it...

Do you want to create a document using windows fonts in Linux? No problem, please install windows fonts using one of mentioned method. Method 1: Copy the *.ttf (True Type Fonts) fonts like Arial, Tahoma, Verdana, Courier New and Times New Roman from the windows partition to the fonts:// location in nautilus. Method 2: For Ubuntu users, and since Ubuntu does not have a...

When your system is rebooted, grub presents the boot option menu called splace screen. From here, you or anybody can easily login into a single user mode (sometimes it is called Rescue Mode) without the password which might result into breaching computer security. You can set a password for the GRUB boot loader. This prevents users from rescue or Singe-User  mode or changing settings at boot ...

You can easily block SSH server attacks including dictionary based attacks and brute force attacks using a Python based script - DenyHosts. It analyzes the sshd log messages to determine what hosts or IPs are attempting to hack into your system. STEP 1: Enable Rpmforge Repo in your system, For 32bit CentOS / RHEL Linux enter: # rpm -Uhv...

SARG – Squid Analysis Report Generator Configuration is a tool that allow you to view “where” your users are going to on the Internet. SARG provides many information about Squid users activities like, times, bytes, sites, etc… Download latest version of SARG from here. # wget http://...

Google has recently released their very own DNS resolver with main goals of making web browsing faster and safer. Since Google's search engine already crawls the web on a daily basis and in the process resolves and caches DNS information, they wanted to make use of their technology to experiment with new ways of addressing some of the existing DNS challenges around performance and security. For advanced...

The iostat command, Report Central Processing Unit (CPU) statistics and input/output statistics for devices, partitions and network file systems (NFS). The iostat command generates reports that can be used to change system configuration to better balance the input/output load between physical disks. The -n option displays the NFS disk statistics. Data displayed are valid only with kernels...

After downloading ISO file from Fedora/CentOS, you can check the integrity of the ISO-file with a checksum, the md5sum. The mirror will offer you a separate text file to download with a 128 bit string of characters. This string has to be exactly the same as the one you get when you do: # md5sum file.iso 0c0f8ff9b6fb60a4778288de0d9e7f46  file.iso We assume that, you have downloaded ...

MySQL is a simple SQL shell (with GNU read line capabilities). It supports interactive and non interactive use. When used interactively, query results are presented in an ASCII-table format. When used non interactively (for example, as a filter), the result is presented in tab-separated format. The output format can be changed using command options. After Installation of MySQL on Linux System, start it by, #...

You may have heard of a server system called LAMP, and wondered what it is. Well, the answer is that LAMP isn't any one thing on its own - it's actually a combination of four technologies. Together, the LAMP technologies form the most popular overall server system on the web today. LAMP is short for Linux, Apache, MySQL, PHP. This will guide you to install LAMP server on your Linux System. Note: I...

“ViCompress HTTP proxy server reduces download time by gzip compressing text pages before sending them on the client. This results in faster download times, especially over slow network connections. ViCompress works with existing web servers and web browsers. All modern browsers (Internet Explorer, Firefox, Safari, Chrome) recognize gzip-encoded data, and will automatically decompress the data on the f...

Squid is a proxy server and web cache daemon. It has a wide variety of uses, from speeding up a web server by caching repeated requests; to caching web, DNS and other computer network lookups for a group of people sharing network resources; to aiding security by filtering traffic.  Once after you have configured Squid, you may notice at the bottom of error page signature appears with GMT timezone. You might...

In Linux you can use faillog command to display failed login attempts or you can set login failure limits. faillog formats the contents of the failure log from /var/log/faillog database / secure log file. It also can be used for maintains failure counters and limits. For RHEL/CentOS Linux 5.x, you need to modify /etc/pam.d/system-auth file to monitor or track failed login attempts. You need to...