RRDtool is the Open Source industry standard, high performance data logging and graphing system for time series data. Use it to write your custom monitoring shell scripts or create whole applications using its Perl, Python, Ruby, TCL or PHP bindings. RRDTOOL is required by many network monitoring utilities like cacti, nagios & many others. To install RRDTool CentOS/Red Hat, # wget...

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...

YUM is an interactive, rpm based, package manager. It can automatically perform system updates, including dependency analysis and obsolete processing based on "repository" metadata. It can also perform installation of new packages, removal of old packages and perform queries on the installed and/or available packages among many other commands/services (see below). yum is similar to other high level package ...

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, #...

For mysql, the system administrator user is called root. We will use the mysqladmin utility from a command line to set the new password. Default password is not secured at all. By default in RedHat, Fedora and Centos default password is null. So it is always better to set root password. To set root password, # mysqladmin -u root password XyZ@aBc@123 # mysqladmin -u root -h ...

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...

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...

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...

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:...

There are a number of different ways to do root password recovery on a Linux system. Different distributions make it easier than others. You must be physically in front of the system. For Red Hat and Mandrake: Boot from your first install CD and as the very first screen comes up hit F2 and type: rescue ( For RedHat "linux rescue" ) and the computer will boot in rescue mode....

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://...

You can convert DEB file to RPM package and RPM to DEB package using alien command, if you have a *.rpm file that you want to install on a Debian or Ubuntu. Convert RPM to DEB Install alien command on Ubuntu as mentioned here: # sudo apt-get install alien Now, use alien command to convert rpm to deb file, # alien...

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, ...

Single-User mode is used for a system recovery. However, by default, no authentication is used if single-user mode is selected. This can be used to bypassing security on the server and gaining root access. To enable authentication for single-user mode, open the /etc/inittab, file: # vi /etc/inittab Add the following line to the...

“MemCached” is a high-performance, distributed memory object caching system, generic in nature, but intended for use in speeding up dynamic web applications by alleviating database load.  Activate the RPMForge repository, #wget http://packages.sw.be/rpmforge-release/rpmforge-release-0.5.2-2.el5.rf.i386.rpm # rpm -ivh rpmforge-release-0.5.2-2.el5.rf.i386.rpm Now install memcache rpm from rpm...

 In RedHat/CentOS/Fedora, software are packaged in .rpm format. rpm is a powerful Package Manager, which can be used to build, install, query, verify, update, and erase individual software packages. A package consists of an archive of files and meta-data used to install and erase the archive files. The meta-data includes helper scripts, file attributes, and descriptive information about the package. Packages...

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...

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:...

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,...

SparkleShare is a syncing and collaboration tool that shines by its absence. it's designed to get out of your way, to make sharing documents and collaboration easier, and to make peers aware of what you are doing says its project site. With SparkleShare, you are given an option to host your remote folder on your own server, Github, Gitorious, The GNOME Project. Sharing...

Mozilla Firefox is a free and open source web browser descended from the Mozilla Application Suite and managed by Mozilla Corporation. As of October 2010, Firefox is the second most widely used browser, with 30% of worldwide usage share of web browsers. In Germany, Firefox is the most popular browser with 60% usage says Wikipedia. To install Firefox 4 on Fedora Linux, # vim ...

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...

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...

Nginx quickly delivers static content with efficient use of system resources. It can deploy dynamic HTTP content on a network using FastCGI handlers for scripts, and can serve as a very capable software load balancer. Nginx uses an asynchronous event-driven approach to handling requests which provides more predictable performance under load, in contrast to the Apache HTTP server model that uses a threaded or...

An ISO image is an disk image of an optical disc using a conventional ISO format. ISO image files typically have a file extension of .ISO. The name "ISO" is taken from the ISO 9660 file system used with CD-ROM media, but an ISO image can also contain UDF file system because UDF is backward-compatible to ISO 9660. You can mount an ISO images via the loop device under Linux. To mount ISO...