Fileop utility does file operation on the filesystem and gives the ops/sec for each operation. This tool will be useful to test your filesystem performance as well as storage performance. Or, if you are going to select a filesystem or storage that is going to host huge number of small files (like source codes), then fileop can be used for benchmarking. First Install  ...

In computer science, Memory Leakage occurs when a computer software or program consumes required memory but unable to memory after completing its task or when no longer needed to Operating System. There are two types of Memory Leakage. One is Virtual Memory Leakage and another is Real Memory Leakage. Now first Identify cached memory or unused memory by executing, ...

When you install a dual-boot of Linux, one of the frustrating things that you’ll immediately notice is that Linux is set as the default operating system in the Grub loader. If you want to change default Operation System instead of Linux, there’s an easy way to switch back to using Windows as the default. Open /boot/grub/menu.lst, # vim /bo...

Wireshark Network Analyzer is use full to track network packets. To sniff MySQL packets and decoding it, we will use mysqlsniffer. Note: This will not usually work for local connections. First, install libpcap-dev, which is the development library that allows an application to sniff network packets. $ sudo  apt-get install ...

For Authentication, Account Management and Authorization, PAM is the core module and pam_unix provides mentioned functionality. Same module can be used to maintain a list of old passwords for every user. This is useful if you want to disallow use of old passwords. You can find out old password list from /etc/security/opasswd file. Open /etc/pam.d/system-auth file of Fedora Core or Red Hat or...

Nikto is a web server scanner tool, which performs comprehensive checking against web servers for multiple items, including over 3500 potentially dangerous files/CGIs, versions on over 700 servers, and version specific problems more than 200 servers. Nikto is built on LibWhisker and can run on any platform which has a Perl environment, and supports SSL, proxies, host authentication, IDS...

The Multi Router Traffic Grapher (MRTG) is a network or resource monitoring tool used by System Administrators across the Globe. MRTG generates HTML pages containing PNG images, which provides a real time visual representation of network traffic and system resources. STEP 1: Install MRTG with required packages # yum install mrtg net-snmp net-snmp-utils -y STEP 2:...

Rsync is a fast and extraordinarily versatile file copying tool. It can copy locally, to/from another host over any remote shell, or to/from a remote rsync daemon. It offers a large number of options that control every aspect of its behaviour and permit very flexible specification of the set of files to be copied. It is famous for its delta-transfer algorithm, which reduces the amount of data...

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...

Swap space in Linux is used when the amount of physical memory (RAM) is full. If the system needs more memory resources and the RAM is full, inactive pages in memory are moved to the swap space. While swap space can help machines with a small amount of RAM, it should not be considered a replacement for more RAM. Swap space is located on hard drives, which have a slower access time than physical...

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...

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: ...

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...

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...

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...

Linux kernel has PC speaker bell driver called pcspkr.ko. It is responsible for generating beeps while users are working on Shell Prompts ( Both Virtual and GUI Terminals ). If you don't like it, simply remove driver from kernel. Login as a root and type the following command to unload the driver: # rmmod -v pcspkr Sample output: rmmod pcspkr, wait=no We...

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...

In computer terminology, a honeypot is a trap set to detect, deflect, or in some manner counteract attempts at unauthorized use of information systems. Generally it consists of a computer, data, or a network site that appears to be part of a network, but is actually isolated, (un)protected, and monitored, and which seems to contain information or a resource of value to attackers. STEP 1:...

If you run a dual-boot system with Linux and Windows, and reinstalling Windows XP after OS corrupt.  Windows XP will wipes over write grub entry or writing MBR sector. To recover GRUB, STEP 1: Boot off the Live CD enter into rescue mode, STEP 2: Open a Terminal and type in the following commands, noting that the first command will put you into the grub “prompt”, and ...

Fedora, CentOS and RHEL allow the console user to perform an interactive system start-up by pressing [I] key. Using interactive boot, attacker can disable the security services and may get access to system. Open etc/sysconfig/init file and disable PROMPT option, # vim /etc/sysconfig/init PROMPT=no Now restart the system and...

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...

By default, MySQL only allows connections from the localhost address – 127.0.0.1. The configuration file is usually found in /etc/my.cnf. To switch MySQL to listen on TCP, Open /etc/my.cnf or /etc/mysql/my.cnf. # vim /etc/my.cnf Modify line as below # bind-address  = 127.0.0.1 Save and Exit the file. Now restart the database server by executing, # /e...

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...

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, #...

Reading or accessing NTFS partitions in Linux is important for many reasons. NTFS-3G is an open source cross-platform implementation of the Microsoft Windows NTFS file system with read-write support. NTFS-3G often uses the FUSE file system interface, so it can run unmodified on many different operating systems.  Before we start, make sure that you have rpmforge repository configured. If you do not have,...